Perovskite and Conjugated Polymer Wrapped Semiconducting

5 days ago - Department of Chemical Engineering, Pohang University of Science and ... hybrid TFTs, semi-CNTs can provide highway-like transport paths,...
18 downloads 0 Views 2MB Size
Subscriber access provided by ECU Libraries

Article

Perovskite and Conjugated Polymer Wrapped Semiconducting Carbon Nanotube Hybrid Films for High Performance Transistors and Phototransistors Huihui Zhu, Ao Liu, Héctor López Luque, Huabin Sun, Dongseob Ji, and Yong-Young Noh ACS Nano, Just Accepted Manuscript • Publication Date (Web): 07 Mar 2019 Downloaded from http://pubs.acs.org on March 7, 2019

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

Perovskite

and

Conjugated

Polymer

Wrapped

Semiconducting Carbon Nanotube Hybrid Films for High Performance Transistors and Phototransistors Huihui Zhu, §,†,┴ Ao Liu, §,†,┴ Hector Lopez Luque,† Huabin Sun,† Dongseob Ji,† ,§ and Yong-Young Noh, §,* §Department

of Chemical Engineering, Pohang University of Science and Technology (POSTECH),

77 Cheongam-Ro, Nam-Gu, Pohang 37673, Republic of Korea †Department

of Energy and Materials Engineering, Dongguk University, 30 Pildong-ro, 1-gil, Jung-

gu, Seoul 04620, Republic of Korea

ABSTRACT Although organic-inorganic halide perovskites continue to generate considerable interest due to great potentials for various optoelectronic devices, there are some critical obstacles to practical applications, including lead toxicity, relatively low field-effect mobility, and strong hysteresis during operation. This paper proposes a universal approach to significantly improve mobility and operational stability with reduced dual-sweep hysteresis for perovskite based thin film transistors (TFTs) by coupling low dimensional lead-free perovskite material (C6H5C2H4NH3)2SnI4 (hereafter abbreviated as (PEA)2SnI4) with embedded conjugated polymer wrapped semiconducting carbon nanotubes (semi-CNTs). In (PEA)2SnI4/semi-CNT hybrid TFTs, semi-CNTs can provide highwaylike transport paths, enabling smoother carrier transport with less trapping and scattering. We also demonstrate the performance of (PEA)2SnI4/semi-CNT hybrid phototransistors with ultrahigh photoresponsivity (R) of 6.3×104 A/W, and detectivity (D*) of 1.12×1017 Jones, which is about two or three order of magnitudes higher than that of the best devices available to date. The results

1

ACS Paragon Plus Environment

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 25

indicate promising potentials for solution processed perovskite/semi-CNT hybrid platforms, and the developed strategy can be applied for high-performance perovskite nanomaterial optoelectronics.

KEYWORDS: lead-free perovskite, carbon nanotubes, thin film transistors, phototransistors, solution process

Organic-inorganic halide perovskite is a current bright star among semiconducting materials for various optoelectronic applications, including solar cells, light emitting diodes, and photodetectors.1-9 The main advantages of this versatile and attractive material family are not only superior carrier transport inherited from inorganic semiconductors, but also solution processability and flexibility inherited from organic parts.10 Although studies of superior optoelectronic devices using perovskite materials have increased explosively, development of electronic devices, such as thin film transistors (TFTs), is much slower, despite the fact that the first solution processed perovskite TFT was reported almost two decades ago with a two-dimensional (2D) perovskite material (C6H5C2H4NH3)2SnI4 (hereafter abbreviated as (PEA)2SnI4).11 Compared with three-dimensional (3D) counterparts (e.g. CH3NH3PbI3), 2D perovskites are expected to be ideal for TFTs because the 2D layered structure has excellent compatibility with transistors that mainly use a horizontal charge transport. (PEA)2SnI4 is also lead free, meeting the imperative demand for lead free perovskite materials for practical environmental friendly applications, since lead toxicity remains a thorny problem for the long run.12 In addition to improving mobility, reducing anomalous current-voltage hysteresis for different voltage scan directions is another important and imperative challenge for perovskite TFT development, since most TFT applications require identical threshold voltage for continuous operations.13-15 Although the hysteretic behavior of halide perovskite devices is not fully understood yet, several underlying origin factors have been proposed including (i) ferroelectricity because of

2

ACS Paragon Plus Environment

Page 3 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

switchable polarization,16, 17 (ii) ion migration with interfacial field change due to ion accumulation at interfaces,15, 18, 19 (iii) charge transport modulation by scattering, trapping, and detrapping at grain boundaries and other defects,20-23 and/or (iv) tunneling originating from local-heavy doping caused by the electrostatic dipole at a rough interface.24 Therefore, interfacing perovskite films with other functional materials to suppress carrier trapping by defects should be one of the effective methods to reduce hysteresis and achieve enhanced (opto)electronic performance. The conjugated polymer wrapped semiconducting carbon nanotubes (semi-CNTs) with outstanding physical and (opto)electronic properties could be very promising among various candidates.25-34 The highway-like carrier transport tracks provided by semi-CNTs in the hybrid films should be able to reduce the carrier trapping by defects.35 Herein, we report hybrid materials based on coupling lead free perovskite with embedded conjugated polymer (poly(9,9-di-n-dodecylfluorene), PFDD) wrapped semi-CNTs for high performance and stable solution process fabricated TFTs and phototransistors. Adding semi-CNTs to (PEA)2SnI4 films, TFT mobility and hysteresis, as well as operation stability are dramatically improved. The (PEA)2SnI4/semi-CNT hybrid phototransistors exhibited ultrahigh photoresponsivity (6.3×104 A/W) and detectivity (D*) of 1.12×1017 Jones, which is the best of perovskite based phototransistors ever reported.

RESULTS AND DISCUSSION

Figure 1a shows the 2D layered organic-inorganic perovskite (PEA)2SnI4 structure and (PEA)2SnI4/semi-CNT precursor preparation. Prior to device fabrication, we developed a method to prepare uniform hybrid dispersion of perovskite/semi-CNT. We first attempted bare single wall CNTs, but it was challenging to obtain uniform suspension (Figure 1b); we then obtained welldispersed conjugated polymer wrapped semi-CNTs. Wrapping with PFDD polymers enabled uniform semi-CNT dispersion in the solvent. Well-dispersed conjugated polymer wrapped semi-CNT

3

ACS Paragon Plus Environment

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 25

ink (> 99% purity) preparation has been detailed previously,30, 31, 36 and experimental details can be seen in METHODS section.

Figure 1. (a) Schematic of (PEA)2SnI4 perovskite structure, and preparation of (PEA)2SnI4/semi-CNT mixture precursor by bath sonication. (b) Suspensions/solutions of bare CNTs, polymers wrapped semi-CNTs, perovskite, perovskite and semi-CNTs, and perovskite and bare CNTs. (c) Absorption spectra of (PEA)2SnI4

4

ACS Paragon Plus Environment

Page 5 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

precursor with and without semi-CNTs. Inset is the absorption spectrum of semi-CNT suspension. (d) XRD patterns for pure (PEA)2SnI4 and (PEA)2SnI4/semi-CNT hybrid films.

We analyzed UV–Vis–NIR absorption spectra of pure (PEA)2SnI4 solution and (PEA)2SnI4/semiCNT mixture. The absorption spectra of semi-CNTs suspension (Figure 1c, inset) exhibited typical absorption peaks at around 1500–1900 nm (highlighted in purple) and 700–1100 nm (highlighted in orange), assigned to S11 and S22, which are the first and second semiconducting exciton features, respectively.36, 37 Figure 1c shows no semi-CNT absorption peaks in pure (PEA)2SnI4 solution, with S11 and S22 peaks occurring only when 5% semi-CNTs suspension added. Those peaks became stronger as semi-CNTs ratio increased to 10% and 20%, confirming uniform semi-CNT dispersion in the hybrid precursor. Figure S1 shows an enlarged view of typical S22 transition for pure and hybrid precursors. Figure 1d shows X-ray diffraction (XRD) patterns for hybrid films before and after semiCNT addition. The regular peaks at 5.3o, 10.8o, 16.1o, 21.7o, 27.3o, 32.8o, and 38.6o can be assigned to (0 0 l) (l = 2, 4, 6, 8, 10, 12, 14) plane diffractions, respectively, indicating the (PEA)2SnI4 perovskite layered structure. Peak intensity decreased and width broadened slightly (Figure S2) as semi-CNT content increased, suggesting that adding semi-CNTs reduced perovskite crystallization. Film morphology was characterized with scanning electron microscope (SEM), as shown in Figure 2a and 2b. Hybrid film image was collected from (PEA)2SnI4/10% semi-CNT. Pure (PEA)2SnI4 films showed widespread pinholes and gaps, while hybrid ones exhibited interlaced-branches-like morphology due to the well blend of (PEA)2SnI4 and semi-CNTs. Inset of Figure 2a gives the SEM image of pure semi-CNTs, the interlaced network morphology is similar with previously reported polymer wrapped semi-CNTs.33 Transmission electron microscopy (TEM) image and selected area electron diffraction (SAED) patterns of hybrid films (Figure 2c and 2d) also show the blend of (PEA)2SnI4 and semi-CNTs. Note that the contrast of intertwined semi-CNTs inside hybrid parts is much weaker than for the dark gray perovskite main body, and hence difficult to distinguish. Figure S3 shows a typical TEM image for a single CNT to provide easier recognition. Figure 2e shows energy dispersive spectroscopy (EDS) elemental analysis, with strong peaks of Sn and I in the perovskite main part. 5

ACS Paragon Plus Environment

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 25

Figure 2. SEM images of (a) pure (PEA)2SnI4 films and pure semi-CNTs (inset). (b) SEM image, (c) TEM image, (d) SAED patterns, and (e) EDS analysis of (PEA)2SnI4/semi-CNT hybrids.

6

ACS Paragon Plus Environment

Page 7 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

Figure 3. (a) Schemes for (PEA)2SnI4/semi-CNT hybrid TFTs. (b–e) Pure and hybrid TFT transfer characteristics with different semi-CNTs content at a scan rate of 1 V/s.

To evaluate (PEA)2SnI4/semi-CNT hybrid film electrical properties, we first fabricated bottom gate top contact transistors based on solution processed pure perovskite, (PEA)2SnI4 (Figure S4 and 7

ACS Paragon Plus Environment

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 25

S5). Pure (PEA)2SnI4 TFTs exhibited mobility μ = 0.51  0.12 cm2 V-1 s-1 with large hysteresis ΔVH = 14.5 V over consecutive forward and reverse scans. The ΔVH is defined as the difference between gate voltage (VGS) for |IDS| = 1 A between off-to-on and on-to-off, where |IDS| is the absolute value of drain current.38 We developed (PEA)2SnI4/semi-CNT hybrid TFTs consisting of semi-CNTs embedded in (PEA)2SnI4 thin films to provide highway-like carrier transport paths (Figure 3a). Table 1 summarizes typical parameters for pure and hybrid TFTs. Compared with pure (PEA)2SnI4 devices (Figure 3b), (PEA)2SnI4/semi-CNT TFTs (5% semi-CNT content) exhibited improved mobility μ = 0.82 ± 0.17 cm2 V-1 s-1 and reduced dual-sweep hysteresis ΔVH = 9.6 V (Figure 3c). (PEA)2SnI4/semiCNT TFTs with 10% semi-CNT content exhibited 3-fold increased μ = 1.51 ± 0.15 cm2 V-1 s-1 with impressively decreased ΔVH = 1.1 V (Figure 3d). However, increasing semi-CNTs content to 20% reduced composite TFT performance: μ = 1.05 ± 0.20 cm2 V-1 s-1 and ΔVH = 6.4 V (Figure 3e), which should result from increased disordering effect by adding excess semi-CNTs. Table 1. Pure (PEA)2SnI4 and (PEA)2SnI4/semi-CNT hybrid TFT performance. PFDD/Semi -CNT ink (vol%)

μFE (cm2 V-1 s-1)

On/off ratio

0

0.51 ± 0.12

1.0×10

5%

0.82 ± 0.17

0.9×10

10%

1.51 ± 0.15

3.1×10

20%

1.05 ± 0.20

3.2×10

5

5

5

5

SS (V/dec)

ΔVH (V)

VTH (V)

NT (cm-2) 12

2.0 ± 0.1

14.5 ± 0.2 2.72×10

2.1 ± 0.1

9.6 ± 0.1 1.80×10

2.1 ± 0.1

1.1 ± 0.1 2.06×10

2.0 ± 0.1

6.4 ± 0.1 1.20×10

12

11

12

For.

Rev.

20 ± 2

9±1

23 ± 1

17 ± 2

25 ± 2

24 ± 2

23 ± 3

16 ± 2

μFE: Field-effect mobility, SS: Subthreshold swing, ΔVH: Hysteresis, NT: Trap density, VTH: Threshold voltage

Previous studies have shown that solution processed pristine perovskite polycrystalline films generally suffer from structural imperfections, and charge transport modulation by defects is one of the underlying hysteresis causes.20-22 Embedded semi-CNTs in the (PEA)2SnI4/semi-CNT composite are expected to provide fast tracks enabling superior carrier transporting with less scattering or trapping.39 We estimated the charge trap density, NT, for pure and hybrid TFTs according to the relation: NT ~ Ci (ΔVH)/e,40, 41 where Ci is the gate dielectric capacitance (30 nF/cm2). These traps are 8

ACS Paragon Plus Environment

Page 9 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

suggested to be localized at chemical/physical defects, semiconductor grain boundaries, and/or semiconductor-dielectric interfaces, greatly influencing device performance.42 Higher trap state density could reduce the carrier mobility; and/or increase the dual-sweep hysteresis, threshold voltage, and subthreshold slope.41 Table 1 shows that trap density for pure perovskite TFT = 2.72×1012 cm-2, reducing to 1.80×1012 cm-2 for hybrid devices with 5% semi-CNT. This indicates the positive effect of semi-CNTs for smoother carrier transport in polycrystalline perovskite films. Devices with 10% semi-CNT possessed lowest trap density = 2.06×1011 cm-2, consistent with their best TFT performance. Trap density increased to 1.20×1012 cm-2 with excess semi-CNT addition, and device performance degraded accordingly. Similar to perovskite-based photovoltaic devices,43 dualsweep hysteresis in perovskite-based TFTs is also related to voltage sweep speed. We found hysteresis increased when sweeping speed over 1 V/s (see Figure S6). The reason for this is not fully understood yet, and should be further explored, as discussed above. Additionally, pure (PEA)2SnI4 TFT can be regarded as several individual buidling blocks with resistance connected in series. SemiCNTs have very high electrical conductivity, up to ~102 S/m.29 In the hybrid system, semi-CNTs replaced certain (PEA)2SnI4 blocks. Although there was little chance of one semi-CNT bridging the entire channel from source to drain, it would still result in a great reduction of total film resistance, similar to the reports by Liu et al. with oxide/CNT hybrids44 and by Gwinner et al. with polymer/CNT composites.45 Since semi-CNTs were dispersed in toluene, we also added 5, 10, and 20% of toluene respectively into pure perovskite precursors and fabricated TFTs under the same condition. These devices showed similar performance with pristine perovskite ones (Figure S7), confirming again the improvement of perovskite/semi-CNT hybrid devices mainly resulting from semi-CNT contribution. We also investigated transistors with a double layer structure of semi-CNTs and (PEA)2SnI4. Double layer devices exhibited even worse performance than pure perovskite TFTs (Figure S8), probably because compared to smooth SiO2 surface, the substrate surface roughness greatly increased after spin coating semi-CNTs, which hindered subsequent organized layered (PEA)2SnI4 crystal growth.10 9

ACS Paragon Plus Environment

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 25

Figure 4. Stability of pure (PEA)2SnI4 and (PEA)2SnI4/10% semi-CNT hybrid TFTs. (a, b) Cycling bias sweep, and (c) bias stress test. (d) Long term stability of hybrid devices in air (humidity 77-86%) and nitrogen (H2O < 1 ppm, O2 < 1 ppm).

Next, we investigated pure (PEA)2SnI4 and (PEA)2SnI4/10% semi-CNT hybrid TFT operational stability by cycling fabricated devices between on (VGS = -40 V) and off (VGS = +30 V) states with constant drain voltage VDS = -40 V, for 500 cycles. Figures 4a and 4b show that pure (PEA)2SnI4 TFTs had slightly degraded drain current particularly during the first 100 cycles, whereas (PEA)2SnI4/10% semi-CNT devices exhibited more stable operation with almost unchanged on/off current ratio throughout the test cycles. Figure 4c shows bias stress stability testing, presented as normalized drain current, IDS(t)/IDS(0) where t is time and IDS(0) is pristine drain current, under constant bias stress VGS = -40 V, VDS = -40 V for 3000 s. Similarly, hybrid TFTs showed superior stability to pure perovskite transistors with significantly slower and smaller degradation. Thus, (PEA)2SnI4/10% semi-CNT films have lower defect density than pure (PEA)2SnI4 films. In addition to operation stability, long term stability is also important for perovskite based devices. We put 10

ACS Paragon Plus Environment

Page 11 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

freshly prepared (PEA)2SnI4/10% semi-CNT TFTs in ambient air, and a glove box that is only used for film sample storage, respectively, and monitored the performance as a function of storage time. The relative humidity of the ambient atmosphere during testing was fluctuating in the range 77%– 86%. Figure 4d shows the change of TFT on-state drain current with air-exposure and nitrogenexposure time. The current slumped with the air-exposure time and almost lost TFT efficacy after 30 hours, mainly due to the decomposition and oxidation of the perovskite film. By contrast, device performance remained steady with the nitrogen-exposure time extending to 90 days. We also tried to spin coat PMMA and Cytop layer for solid encapsultion, but both did not work well (Figure S9). TFTs degradaded imediately after coating PMMA, either with n-butyl acetate or anisole as the solvent, which should because solvents damaged or stripped the underlying (PEA)2SnI4 layer. Cytopencapsulated devices had no off-state, possibly resulting from Cytop doping effect.46 Despite the poor air stability at present, high inert atmosphere stabiltiy and (opto)electronic performance still make perovskite a very promising material for future applications.

Figure 5. (a) Absorbance of (PEA)2SnI4 films without and with 10% semi-CNT. (b) External quantum efficiency (EQE) spectra at bias voltage of -1 V for pure and hybrid devices.

We next studied the photoresponse behavior of (PEA)2SnI4 films without and with 10% semi-CNT intrigued by unique optoelectronic properties of both materials. Hybrid films exhibited slightly higher absorbance and external quantum efficiency (EQE) across a broad range from visible to near infrared (Figure 5a and 5b). Here, the pure and hybrid perovskite layers were fabricated under the 11

ACS Paragon Plus Environment

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 12 of 25

same condition with that of TFTs. Although without two-terminal device optimization in this primary stage, a maximum EQE value of 16.5% at bias voltage of -1 V was achieved, which is comparable or even superior to previously reported CsPbBr3 nanosheets, illustrating the great photo to charge conversion property of both pure and hybrid systems.47 Based on the previous TFT configuration, we further investigated pure (PEA)2SnI4 and hybrid (PEA)2SnI4/10% semi-CNT device performance as three-terminal phototransistors, which possess superior sensitivity to twoterminal photodetectors, including reduced noise and enhanced electrical signals, and are targeted for image sensing, optical communication, environmental monitoring, and chemical/biological detection.48, 49 Figure 6a and 6b show (PEA)2SnI4 phototransistor transfer characteristics with and without 10% semi-CNT TFTs in dark and light (532 nm, 3 W/cm2) conditions. Both pure and hybrid devices presented significantly higher drain current under illumination than in the dark. (PEA)2SnI4/10% semi-CNT phototransistors exhibited higher photocurrent than that of pure (PEA)2SnI4 devices.

Figure 6. Transfer curves dark and irradiated of (a) pure (PEA)2SnI4 and (b) hybrid (PEA)2SnI4/10% semi-CNT phototransistors. (c) Time-resolved photoluminescence (TRPL) decay of pure and hybrid films. Dashed lines show experimental data fit to a biexponential function.

Charge carrier dynamics in pure and hybrid systems were investigated using time-resolved photoluminescence (TRPL) decay measurements. We studied the temporal evolution of the 12

ACS Paragon Plus Environment

Page 13 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

photoluminescence (PL) emission at 530 nm of pure (PEA)2SnI4 and (PEA)2SnI4/10% semi-CNT composite films spin-coated on glass substrates. Figure 6c shows that TRPL decay can be modeled with the biexponential function:

( )

𝐼(𝑡) = 𝐴1exp ―

( )

𝑡 𝑡 + 𝐴2exp ― 𝜏1 𝜏2

where 𝐼(𝑡) is time-resloved PL intensity, 𝐴1 and 𝐴2 are relative amplitudes, and 𝜏1 and 𝜏2 are lifertimes for fast and slow decays, respectively. A number of previous reports assigned the decays to carrier recombination induced by defects.50-53 Pure (PEA)2SnI4 film exhibited fast and slow state lifetimes of 𝜏1 = 434 ns and 𝜏2 = 10116 ns, whereas hybrid film exhibited 𝜏1 = 5941 ns and 𝜏2 = 13533 ns. The extended lifetime resulted from suppressed carrier trapping by defects in the hybrid system,50 which is in consistent with results and analyses in the TFT section. To evaluate the photo detection performance of pure (PEA)2SnI4 and hybrid (PEA)2SnI4/10% semi-CNT phototransistors in detail, we analyze several essential figure of merit. As an initial step, we studied phototransistor light responsivity. This property is generally quantified by determining photoresponsivity (R) and photo-switching ratio, i.e., photosensitivity (P), which was accomplished by measuring transistor I-V characteristics under white or monochromatic light illumination. R and P are defined as 𝑅 = (𝐼𝑙𝑖𝑔ℎ𝑡 ― 𝐼𝑑𝑎𝑟𝑘)/(𝐸𝑊𝐿), and 𝑃 = (𝐼𝑙𝑖𝑔ℎ𝑡 ― 𝐼𝑑𝑎𝑟𝑘)/𝐼𝑑𝑎𝑟𝑘, where Ilight and Idark are the drain current under light irradiation and dark state, respectively; E is incident illumination power density; and W and L are channel width and length, respectively.54 Figure 7a and 7b show the resultant R and P values as a function of VGS for the fabricated phototransistors. Pure (PEA)2SnI4 phototransistors exhibited R = 8.3×103 A/W and P = 7.2×104, whereas (PEA)2SnI4/10% semi-CNT hybrid devices achieved R = 6.3×104 A/W and P = 4.7×105. Such values are among the best solution processed perovskite based phototransistors ever reported (Table S1). Conventional single crystal Si phototransistors exhibited R = 300 A/W, which was regarded as the assessment reference for a photodetector.55, 56 Wavelength dependent gain can be expressed as Gain = R × Ehv, where R is photoresponsivity corresponding to the incident light wavelength, and Ehv is the energy of the 13

ACS Paragon Plus Environment

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 25

incident photon (in eV).57 We found Gain = 1.5×105 for hybrid devices. Another figure of merit for photodetectors is linear dynamic range (LDR), given by LDR = 20log (𝐼𝑙𝑖𝑔ℎ𝑡 𝐼𝑑𝑎𝑟𝑘). The highest LDR was found to be 113 dB with hybrid devices (Figure 7c), which is much higher than that of InGaAs photodetectors (66 dB) and close to that of a Si photodetector (≈120 dB).

Figure 7. Performance of pure (PEA)2SnI4 and hybrid (PEA)2SnI4/10% semi-CNT phototransistors. (a) Photoresponsivity (R) and (b) photosensitivity (P) under light irradiation, and (c) linear dynamic range (LDR). (d) Gate-dependent noise current density, (e) noise equivalent power (NEP), and (f) detectivity (D*).

In addition to high light responsivity, the low limits of light detection for photodetectors are ascertained by the noise characteristics of the device. The total current noise, IN, generally includes 14

ACS Paragon Plus Environment

Page 15 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

thermal or Johnson noise, IJ; shot noise, IS; and flicker noise, 1/f or contact noise, IF; i.e., 𝐼𝑁 = 𝐼𝐽2 + 𝐼𝑆2 + 𝐼𝐹2.58 IJ was proportional to absolute temperature, 𝐼𝐽 = 4𝑘𝐵𝑇∆𝑓/𝑅𝑆𝐻, where ∆𝑓 is the noise bandwidth (∆𝑓 = 1 in this work), 𝑅𝑆𝐻 is the device shunt resistance and 𝑘𝐵 = 1.38×10-23 J/K is Boltzmann’s constant. IJ can be negligible for room-temperature operated devices,59 whereas IS determined by the photodetector dark current, Idark, according to 𝐼𝑆 = 2𝑞𝐼𝑑𝑎𝑟𝑘∆𝑓; and IF mainly arises from charges being trapped and detrapped, and may dominate IN at low frequencies (1–100 Hz).60, 61 Previous studies have reported measured 1/f noise becomes very close to the calculated shot noise limit for room-temperature low-frequency operated phototransistors near the transistor offstate, when dark current is extremely low due to the applied gate bias,61, 62 which is consistent with noise current density measurement and analysis presented in the current paper (see Figure S10 and detailed discussion in Supporting Information). Pure and hybrid phototransistors exhibited extremely low noise current density with the minimum value on the order of 10-14 A/Hz0.5 (Figure 7d). Noise equivalent power (NEP) is defned as the equivalent optical power generating a signal equal to the noise. It refers to the minimum optical power that a device can detect. Detectivity (D*) is the sensitivity normalized with the active area of a photodetector; thus, it can be used to compare the performance of different photodetecting devices with varied sizes, similar with R.59 The NEP and D* are estimated and shown in Figure 7e and 7f according to the following expressions, NEP = 𝐼𝑁 𝑅, and 𝐷 ∗ = 𝐴 𝑁𝐸𝑃, where A is the device active area (W × L). Calculation shows that the minimum NEP value of hybrid (PEA)2SnI4/10% semi-CNT devices is on the order of 10-19 W/Hz0.5, which is almost two orders of magnitude lower than the reported IGZO/SWCNT phototransistors.63 The maximum value of photodetectivity D* = 1.12×1017 Jones was also achieved with hybrid phototransistors, which is four orders of magnitude higher than that of commercial Si or InGaAs photodiodes (D* ∼1013 Jones) and is about two or three order of magnitudes higher than that of the highest existing devices (Table S1).58

15

ACS Paragon Plus Environment

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 16 of 25

Figure 8. The dynamic photoresponse behavior of pure (PEA)2SnI4 and hybrid (PEA)2SnI4/10% semi-CNT phototransistors. (a, b) Output characteristics under dark and pulsed-light illumination at VGS = 15 V. (c, d) Photo on-off modulation. Here, VDS was set at -40 V; VGS was +40V unless the moment when back gate bias (40 V, 1 s) was applied to eliminate the PPC effect. (e, f) Time-dependent photocurrent response, showing the rise time of 2740 and 825 ms for pure and hybrid phototransistors respectively, and decay time of 435 and 440 ms.

Figure 8 depicts the dynamic photoresponse behavior of pure (PEA)2SnI4 and hybrid (PEA)2SnI4/10% semi-CNT phototransistors. Pure and hybrid phototransistors exhibited clear 16

ACS Paragon Plus Environment

Page 17 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

dynamic response under modulated light irradiation (Figure 8a and 8b), illustrating that light acted as an additional gate to modulate transistor drain current. Similar with previously reported oxide semiconductor

phototransistors,

organic,

and

MoS2

devices,63-65

our

perovskite-based

phototransistors also suffered from light instability such as the PPC effect under illuminated conditions. As shown in Figure 8a and 8b, the remaining PPC effects in pure and hybrid phototransistors may hinder the fast dynamic operation. To enhance dynamic photo-related operation, a pulse back gate bias (-40 V, 1 s) was applied to devices, which can accelerate the recombination of photo-generated holes with the supplied electrons, resulting in sufficient elimination of the PPC phenomenon (Figure 8c and 8d),63 thus reducing drain current to dark state level. Compared with pure phototransistors, hybrid devices possessed superior response speed with less than a third rising time (Figure 8e and 8f), which is also an evidence for smoother carrier transport in (PEA)2SnI4/semiCNT hybrid systems.

CONCLUSION In conclusion, we reported the processing of 2D layered perovskite materials (PEA)2SnI4 and conjugated polymer wrapped semi-CNTs hybrid transistors. Compared to pure (PEA)2SnI4 counterparts, hybrid devices with semi-CNTs as smooth carrier transport tracks showed greatly reduced dual-sweep hysteresis, improved field-effect mobility, and higher operation stability due to less carrier trapping and scattering. We also demonstrated the performance of (PEA)2SnI4/semi-CNT hybrid phototransistor including the record high detectivity. On the basis of intrinsic (PEA)2SnI4 optoelectronic features, such photodetecting behavior mainly benefited from the supressed carrier trapping by defects in (PEA)2SnI4/semi-CNT hybrids. This strategy of low dimensionality Sn(II) perovskites and semi-CNTs hybrid systems offers promising prospects for high performance leadfree perovskite/nanomaterial based optoelectronics.

17

ACS Paragon Plus Environment

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 18 of 25

METHODS Perovskite/CNT precursor preparation. Phenethylammonium iodide (PEAI, Xi’an Polymer Light Technology Corp.) and SnI2 (Alfa Aesar) were dissolved in dimethylformamide at 2:1 stoichiometric molar ratio and held at 60°C for 2h in a glove box. For bare carbon nanotubes (CNT, RN220, Nanointegris Inc.) dispersion, 0.25 mg single walled CNT were added to 10 ml toluene then dispersed for 1 h by tip sonicator (Sonics & Materials Inc., VCX-130, 130 W) in a cool bath. For polymer wrapped semiconducting carbon nanotubes (semiCNTs) dispersion, poly(9,9-di-n-dodecylfluorene) (PFDD) polymers were added to 20 ml toluene at 0.5 mg/ml, and then bath sonicated for 10 min. After the polymer completely dissolved, 20 mg single walled CNTs were added to the solution and dispersed for 1 h by tip sonicator in a cool bath. During sonication, polymers selectively wrapped semi-CNTs and dispersed within the solution. To separate only semi-CNTs, the suspension was centrifuged at a relative centrifugal force RCF = 85000 g for 1 h (Hanil Scientific Inc., Supra R30), leaving metallic CNT and impurities as sediment, whereas dispersed semi-CNTs and PFDD polymers remained within the solution. First filtration used 6 m filter paper to separate the suspension and sediment followed by second filtration with 0.20 m MCE membrane to remove the polymers. Semi-CNTs embedded in the membrane were redispersed in 7 ml toluene by bath sonication for 5 min. For (PEA)2SnI4/semi-CNT precursor, 5, 10, and 20 vol% semi-CNT suspension was added to 0.5 ml pure (PEA)2SnI4 solution in a glove box. Mixture suspensions were bath sonicated for 30 min prior to use. Device fabrication. Si/SiO2 (100 nm, 1.5×1.5 cm) or ITO (2.5×2.5 cm) substrates were cleaned by ultrasonic bath with acetone, isopropanol, and deionized water, consecutively for 10 min each. After drying in flowing nitrogen and vacuum oven, substrates were treated with UV/ozone for 30 min. For TFTs, pure (PEA)2SnI4 solution or (PEA)2SnI4/semi-CNT mixture precursor suspension with different semi-CNTs ratios were then deposited by spin coating at 4000 rpm for 30 s, and annealed at 100°C for 10 min in a glove box. Finally, Au (40 nm) source (S) and drain (D) electrodes were 18

ACS Paragon Plus Environment

Page 19 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

deposited by thermal evaporation through a shadow mask, constructing 100×1000 μm (length×width) transistor channels. For EQE measurement, prior to perovskite layer coating, PEDOT:PSS was spin coated at 5000 rpm and annealed at 150 °C for 15 min; after perovskite layer coating, PCBM was deposited by spin coating at 1500 rpm and annealed at 100 °C for 5 min. Device fabrication was completed with LiF/Al (1nm/100nm) electrodes thermally evaporated. Characterization. Transistor transfer and output characteristics at room temperature in dark and light states were measured using a semiconductor parameter analyzer (Keithley 4200-SCS). Light irradiation was achieved with light-emitting diodes (532 nm, 3 W/cm2). All the above operations were performed in a nitrogen filled glove box. EQE was analyzed using Solar Cell QE Test system (Mc Science, K3100). The SiO2 (100 nm) dielectric layer capacitance was measured to be 30 nF/cm2. Film XRD patterns were recorded using a Rigaku D/MAX 2600 V with Cu K ( = 1.5406 Å) radiation. SEM and TEM images were obtained using a field-emission scanning electron microscope (Hitachi S4800) and a field-emission transmission electron microscope (FEI Tecnai F20 G2 STWIN), respectively. UV–Vis–NIR absorbance spectra were measured using a spectrophotometer (JASCO V-770). The TRPL measurements were performed in a FS5 Spectrofluorometer system with an excitation at 325 nm.

ASSOCIATED CONTENT The authors declare no competing financial interest. Supporting Information Additional experimental details and figures. This material is available free of charge on http://pubs.acs.org.

AUTHOR INFORMATION Corresponding Authors *Email: [email protected] 19

ACS Paragon Plus Environment

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 20 of 25

Author Contributions ┴Huihui

Zhu and Ao Liu contributed equally to this work.

ACKNOWLEDGMENTS This study was supported by the Ministry of Science & ICT through the NRF grant funded by the Korea government (2017R1E1A1A01075360) and the Center for Advanced Soft-Electronics (2013M3A6A5073183).

REFERENCES (1)

Qi, J.; Zema, C.; Pengyang, W.; Xiaolei, Y.; Heng, L.; Ye, W.; Zhigang, Y.; Jinliang, W.; Xingwang, Z.; Jingbi, Y., Planar-Structure Perovskite Solar Cells with Efficiency Beyond 21%. Adv. Mater. 2017, 29, 1703852.

(2)

Burschka, J.; Pellet, N.; Moon, S.-J.; Humphry-Baker, R.; Gao, P.; Nazeeruddin, M. K.; Grätzel, M., Sequential Deposition as a Route to High-Performance Perovskite-Sensitized Solar Cells. Nature 2013, 499, 316.

(3)

Chen, C.; Zhang, X.; Wu, G.; Li, H.; Chen, H., Visible- Light Ultrasensitive SolutionPrepared Layered Organic-Inorganic Hybrid Perovskite Field-Effect Transistor. Adv. Opt. Mater. 2017, 5, 1600539.

(4)

Shao, S.; Cui, Y.; Duim, H.; Qiu, X.; Dong, J.; Ten Brink, G. H.; Portale, G.; Chiechi, R. C.; Zhang, S.; Hou, J.; Loi, M. A., Enhancing the Performance of the Half Tin and Half Lead Perovskite Solar Cells by Suppression of the Bulk and Interfacial Charge Recombination. Adv. Mater. 2018, 0, e1803703.

(5)

Yang, Z.; Feng, W.; Yu, C.; Jian-Pu, W.; Hong-Hua, F.; Antonietta, L. M.; Ni, Z.; ChingPing, W., Benzylamine-Treated Wide-Bandgap Perovskite with High Thermal-Photostability and Photovoltaic Performance. Adv. Energy Mater. 2017, 7, 1701048.

(6)

Zhang, L.; Yang, X.; Jiang, Q.; Wang, P.; Yin, Z.; Zhang, X.; Tan, H.; Yang, Y. M.; Wei, M.; Sutherland, B. R., Ultra-Bright and Highly Efficient Inorganic Based Perovskite LightEmitting Diodes. Nat. Commun. 2017, 8, 15640.

(7)

Wang, N.; Cheng, L.; Ge, R.; Zhang, S.; Miao, Y.; Zou, W.; Yi, C.; Sun, Y.; Cao, Y.; Yang, R., Perovskite Light-Emitting Diodes Based on Solution-Processed Self-Organized Multiple Quantum Wells. Nat. Photonics 2016, 10, 699.

(8)

Milan, V.; Clemens, M.; Aditya, S.; Giorgio, D.; Stefania, C.; E., D. S.; Caterina, D.; Mete, A.; Henry, S.; H., F. R.; Henning, S.; Felix, D., Local Versus Long-Range Diffusion Effects of Photoexcited States on Radiative Recombination in Organic-Inorganic Lead Halide Perovskites. Adv. Sci. 2015, 2, 1500136.

(9)

Liu, Q.; Yilin, S.; Mingmao, W.; Dan, X.; Liming, D.; Gaoquan, S., A Solution-Processed High-Performance Phototransistor Based on a Perovskite Composite with Chemically Modified Graphenes. Adv. Mater. 2017, 29, 1606175.

20

ACS Paragon Plus Environment

Page 21 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

(10)

Matsushima, T.; Hwang, S.; Sandanayaka, A. S.; Qin, C.; Terakawa, S.; Fujihara, T.; Yahiro, M.; Adachi, C., Solution-Processed Organic-Inorganic Perovskite Field-Effect Transistors with High Hole Mobilities. Adv. Mater. 2016, 28, 10275-10281.

(11)

Kagan, C.; Mitzi, D.; Dimitrakopoulos, C., Organic-Inorganic Hybrid Materials as Semiconducting Channels in Thin-Film Field-Effect Transistors. Science 1999, 286, 945-947.

(12)

Qian, L.; Sun, Y.; Wu, M.; Li, C.; Xie, D.; Ding, L.; Shi, G., A Lead-Free Two-Dimensional Perovskite for a High-Performance Flexible Photoconductor and a Light-Stimulated Synaptic Device. Nanoscale 2018, 10, 6837-6843.

(13)

Chin, X. Y.; Cortecchia, D.; Yin, J.; Bruno, A.; Soci, C., Lead Iodide Perovskite LightEmitting Field-Effect Transistor. Nat. Commun. 2015, 6, 7383.

(14)

Labram, J. G.; Fabini, D. H.; Perry, E. E.; Lehner, A. J.; Wang, H.; Glaudell, A. M.; Wu, G.; Evans, H.; Buck, D.; Cotta, R., Temperature-Dependent Polarization in Field-Effect Transport and Photovoltaic Measurements of Methylammonium Lead Iodide. J. Phys. Chem. Lett. 2015, 6, 3565-3571.

(15)

Senanayak, S. P.; Yang, B.; Thomas, T. H.; Giesbrecht, N.; Huang, W.; Gann, E.; Nair, B.; Goedel, K.; Guha, S.; Moya, X., Understanding Charge Transport in Lead Iodide Perovskite Thin-Film Field-Effect Transistors. Sci. Adv. 2017, 3, e1601935.

(16)

Wei, J.; Zhao, Y.; Li, H.; Li, G.; Pan, J.; Xu, D.; Zhao, Q.; Yu, D., Hysteresis Analysis Based on the Ferroelectric Effect in Hybrid Perovskite Solar Cells. J. Phys. Chem. Lett. 2014, 5, 3937-3945.

(17)

Seol, D.; Jeong, A.; Han, M. H.; Seo, S.; Yoo, T. S.; Choi, W. S.; Jung, H. S.; Shin, H.; Kim, Y., Origin of Hysteresis in CH3NH3PbI3 Perovskite Thin Films. Adv. Funct. Mater. 2017, 1701924.

(18)

Meloni, S.; Moehl, T.; Tress, W.; Franckevičius, M.; Saliba, M.; Lee, Y. H.; Gao, P.; Nazeeruddin, M. K.; Zakeeruddin, S. M.; Rothlisberger, U., Ionic Polarization-Induced Current-Voltage Hysteresis in CH3NH3PbX3 Perovskite Solar Cells. Nat. Commun. 2016, 7, 10334.

(19)

Li, C.; Tscheuschner, S.; Paulus, F.; Hopkinson, P. E.; Kießling, J.; Köhler, A.; Vaynzof, Y.; Huettner, S., Iodine Migration and Its Effect on Hysteresis in Perovskite Solar Cells. Adv. Mater. 2016, 28, 2446-2454.

(20)

Miller, D. W.; Eperon, G. E.; Roe, E. T.; Warren, C. W.; Snaith, H. J.; Lonergan, M. C., Defect States in Perovskite Solar Cells Associated with Hysteresis and Performance. Appl. Phys. Lett. 2016, 109, 6050.

(21)

Son, D.-Y.; Lee, J.-W.; Choi, Y. J.; Jang, I.-H.; Lee, S.; Yoo, P. J.; Shin, H.; Ahn, N.; Choi, M.; Kim, D.; Park, N.-G., Self-Formed Grain Boundary Healing Layer for Highly Efficient CH3NH3PbI3 Perovskite Solar Cells. Nat. Energy 2016, 1, 16081.

(22)

Lee, J.-W.; Kim, S.-G.; Bae, S.-H.; Lee, D.-K.; Lin, O.; Yang, Y.; Park, N.-G., The Interplay between Trap Density and Hysteresis in Planar Heterojunction Perovskite Solar Cells. Nano Lett. 2017, 17, 4270-4276.

(23)

Son, D.-Y.; Kim, S.-G.; Seo, J.-Y.; Lee, S.-H.; Shin, H.; Lee, D.; Park, N.-G., Universal Approach Toward Hysteresis-Free Perovskite Solar Cell via Defect Engineering. J. Am. Chem. Soc. 2018, 140, 1358-1364.

(24)

Lee, H.; Gaiaschi, S.; Chapon, P.; Marronnier, A.; Lee, H.; Vanel, J. C.; Tondelier, D.; Boureé, J. E.; Bonnassieux, Y.; Geffroy, B., Direct Experimental Evidence of Halide Ionic Migration under Bias in CH3NH3PbI3-xClx Based Perovskite Solar Cells Using GD-OES Analysis. ACS Energy Lett. 2017, 2, 943-949. 21

ACS Paragon Plus Environment

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 22 of 25

(25)

Li, F.; Wang, H.; Kufer, D.; Liang, L.; Yu, W.; Alarousu, E.; Ma, C.; Li, Y.; Liu, Z.; Liu, C., Ultrahigh Carrier Mobility Achieved in Photoresponsive Hybrid Perovskite Films via Coupling with Single-Walled Carbon Nanotubes. Adv. Mater. 2017, 29, 1602432.

(26)

Qian, L.; Sun, Y.; Wu, M.; Xie, D.; Ding, L.; Shi, G., A Solution-Processed HighPerformance Phototransistor Based on a Perovskite Composite with Chemically Modified Graphenes. Adv. Mater. 2017, 29.

(27)

Roy, K.; Padmanabhan, M.; Goswami, S.; Sai, T. P.; Ramalingam, G.; Raghavan, S.; Ghosh, A., Graphene-MoS2 Hybrid Structures for Multifunctional Photoresponsive Memory Devices. Nat. Nanotechnol. 2013, 8, 826.

(28)

Tans, S. J.; Verschueren, A. R.; Dekker, C., Room-Temperature Transistor Based on a Single Carbon Nanotube. Nature 1998, 393, 49.

(29)

Zhou, X.; Park, J.-Y.; Huang, S.; Liu, J.; McEuen, P. L., Band Structure, Phonon Scattering, and the Performance Limit of Single-Walled Carbon Nanotube Transistors. Phys. Rev. Lett. 2005, 95, 146805.

(30)

Ji, D.; Lee, S.-H.; Noh, Y.-Y., Selective Dispersion of High-Purity Semiconducting Carbon Nanotubes Using Indacenodithiophene-Based Conjugated Polymer. Appl. Phys. Lett. 2018, 112, 033103.

(31)

Graf, A.; Held, M.; Zakharko, Y.; Tropf, L.; Gather, M. C.; Zaumseil, J., Electrical Pumping and Tuning of Exciton-Polaritons in Carbon Nanotube Microcavities. Nat. Mater. 2017, 16, 911.

(32)

Mario, S.-R. J.; Wytse, T.; Vladimir, D.; Widianta, G.; Tina, K.; Martin, F.; Sebastian, K.; Eduard, P.; Ming, W.; Sybille, A.; Carlos, B. G.; Ullrich, S.; Cristina, d. S. M.; Antonietta, L. M., Understanding the Selection Mechanism of the Polymer Wrapping Technique toward Semiconducting Carbon Nanotubes. Small Methods 2018, 2, 1700335.

(33)

Schießl, S. P.; Fröhlich, N.; Held, M.; Gannott, F.; Schweiger, M.; Forster, M.; Scherf, U.; Zaumseil, J., Polymer-Sorted Semiconducting Carbon Nanotube Networks for HighPerformance Ambipolar Field-Effect Transistors. ACS Appl. Mater. Interfaces 2015, 7, 682689.

(34)

Ihly, R.; Dowgiallo, A. M.; Yang, M.; Schulz, P.; Stanton, N.; Reid, O. G.; Ferguson, A.; Zhu, K.; Berry, J. J.; Blackburn, J., Efficient Charge Extraction and Slow Recombination in Organic-Inorganic Perovskites Capped with Semiconducting Single-Walled Carbon Nanotubes. Energy Environ. Sci. 2016, 9, 1439-1449.

(35)

Li, X.; Yu, D.; Chen, J.; Wang, Y.; Cao, F.; Wei, Y.; Wu, Y.; Wang, L.; Zhu, Y.; Sun, Z., Constructing Fast Carrier Tracks into Flexible Perovskite Photodetectors to Greatly Improve Responsivity. ACS Nano 2017, 11, 2015-2023.

(36)

Park, N.-H.; Lee, S.-H.; Jeong, S.-H.; Khim, D.; Kim, Y. H.; Yoo, S.; Noh, Y.-Y.; Kim, J.-J., Heterostructured Semiconductor Single-Walled Carbon Nanotube Films for SolutionProcessed High-Performance Field-Effect Transistors. Semicond. Sci. Tech. 2018, 33, 035017.

(37)

Lee, S.-H.; Kim, D.-Y.; Noh, Y.-Y., Solution-Processed Polymer-Sorted Semiconducting Carbon Nanotube Network Transistors with Low-k/High-k Bilayer Polymer Dielectrics. Appl. Phys. Lett. 2017, 111, 123103.

(38)

Furuta, M.; Kawaharamura, T.; Wang, D.; Toda, T.; Hirao, T., Electrical Properties of the Thin-Film Transistor with an Indium-Gallium-Zinc Oxide Channel and an Aluminium Oxide Gate Dielectric Stack Formed by Solution-Based Atmospheric Pressure Deposition. IEEE Electron Device Lett. 2012, 33, 851-853. 22

ACS Paragon Plus Environment

Page 23 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

(39)

Javey, A.; Guo, J.; Wang, Q.; Lundstrom, M.; Dai, H., Ballistic Carbon Nanotube FieldEffect Transistors. Nature 2003, 424, 654.

(40)

Wang, A.; Kymissis, I.; Bulovic, V.; Akinwande, A. I., Engineering Density of Semiconductor-Dielectric Interface States to Modulate Threshold Voltage in OFETs. IEEE. T. Electron Dev. 2006, 53, 9-13.

(41)

Zhang, L.; Li, J.; Zhang, X.; Jiang, X.; Zhang, Z., High Performance Zno-Thin-Film Transistor with Ta2O5 Dielectrics Fabricated at Room Temperature. Appl. Phys. Lett. 2009, 95, 072112.

(42)

Yoon, M.-H.; Kim, C.; Facchetti, A.; Marks, T. J., Gate Dielectric Chemical StructureOrganic Field-Effect Transistor Performance Correlations for Electron, Hole, and Ambipolar Organic Semiconductors. J. Am. Chem. Soc. 2006, 128, 12851-12869.

(43)

Tress, W.; Marinova, N.; Moehl, T.; Zakeeruddin, S. M.; Nazeeruddin, M. K.; Grätzel, M., Understanding the Rate-Dependent J-V Hysteresis, Slow Time Component, and Aging in CH3NH3PbI3 Perovskite Solar Cells: The Role of a Compensated Electric Field. Energy Environ. Sci. 2015, 8, 995-1004.

(44)

Liu, X.; Wang, C.; Cai, B.; Xiao, X.; Guo, S.; Fan, Z.; Li, J.; Duan, X.; Liao, L., Rational Design of Amorphous Indium Zinc Oxide/Carbon Nanotube Hybrid Film for Unique Performance Transistors. Nano Lett. 2012, 12, 3596-3601.

(45)

Gwinner, M. C.; Jakubka, F.; Gannott, F.; Sirringhaus, H.; Zaumseil, J., Enhanced Ambipolar Charge Injection with Semiconducting Polymer/Carbon Nanotube Thin Films for LightEmitting Transistors. ACS Nano 2012, 6, 539-548.

(46)

Park, M.; Kwon, K. C.; Hyeon Oh, J.; Kim, Y. G.; Jang, H. W.; Kim, S. Y., Effect of Fluoropolymer Assisted Transfer on Graphene Doping. Sci. Adv. Mater. 2017, 9, 758-764.

(47)

Song, J.; Xu, L.; Li, J.; Xue, J.; Dong, Y.; Li, X.; Zeng, H., Monolayer and Few-Layer AllInorganic Perovskites as a New Family of Two-Dimensional Semiconductors for Printable Optoelectronic Devices. Adv. Mater. 2016, 28, 4861-4869.

(48)

Wang, H.; Kim, D. H., Perovskite-Based Photodetectors: Materials and Devices. Chem. Soc. Rev. 2017, 46, 5204-5236.

(49)

Kang-Jun, B.; Maddalena, B.; Dario, N.; Mario, C.; Yong-Young, N., Organic Light Detectors: Photodiodes and Phototransistors. Adv. Mater. 2013, 25, 4267-4295.

(50)

Zheng, X.; Deng, Y.; Chen, B.; Wei, H.; Xiao, X.; Fang, Y.; Lin, Y.; Yu, Z.; Liu, Y.; Wang, Q.; Huang, J., Dual Functions of Crystallization Control and Defect Passivation Enabled by Sulfonic Zwitterions for Stable and Efficient Perovskite Solar Cells. Adv. Mater. 0, 1803428.

(51)

Bi, D.; Li, X.; Milić, J. V.; Kubicki, D. J.; Pellet, N.; Luo, J.; LaGrange, T.; Mettraux, P.; Emsley, L.; Zakeeruddin, S. M.; Grätzel, M., Multifunctional Molecular Modulators for Perovskite Solar Cells with over 20% Efficiency and High Operational Stability. Nat. Commun. 2018, 9, 4482.

(52)

Bi, D.; Yi, C.; Luo, J.; Décoppet, J.-D.; Zhang, F.; Zakeeruddin, Shaik M.; Li, X.; Hagfeldt, A.; Grätzel, M., Polymer-Templated Nucleation and Crystal Growth of Perovskite Films for Solar Cells with Efficiency Greater Than 21%. Nat. Energy 2016, 1, 16142.

(53)

Yang, W. S.; Noh, J. H.; Jeon, N. J.; Kim, Y. C.; Ryu, S.; Seo, J.; Seok, S. I., HighPerformance Photovoltaic Perovskite Layers Fabricated through Intramolecular Exchange. Science 2015, 348, 1234.

(54)

Rekab, W.; Stoeckel, M.-A.; El Gemayel, M.; Gobbi, M.; Orgiu, E.; Samorì, P., HighPerformance Phototransistors Based on PDIF-CN2 Solution-Processed Single Fiber and Multifiber Assembly. ACS Appl. Mater. Interfaces 2016, 8, 9829-9838. 23

ACS Paragon Plus Environment

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 24 of 25

(55)

Johnson, N. M.; Chiang, A., Highly Photosensitive Transistors in Single-Crystal Silicon Thin Films on Fused Silica. Appl. Phys. Lett. 1984, 45, 1102-1104.

(56)

Yutaka, W.; Ryoma, H.; Hoon-Seok, S., Recent Progress in Photoactive Organic Field-Effect Transistors. Sci. Technol. Adv. Mater. 2014, 15, 024202.

(57)

Dong, R.; Fang, Y.; Chae, J.; Dai, J.; Xiao, Z.; Dong, Q.; Yuan, Y.; Centrone, A.; Zeng, X. C.; Huang, J., High-Gain and Low-Driving-Voltage Photodetectors Based on Organolead Triiodide Perovskites. Adv. Mater. 2015, 27, 1912-1918.

(58)

Nie, R.; Deng, X.; Feng, L.; Hu, G.; Wang, Y.; Yu, G.; Xu, J., Highly Sensitive and Broadband Organic Photodetectors with Fast Speed Gain and Large Linear Dynamic Range at Low Forward Bias. Small 2017, 13, 1603260.

(59)

Huang, L.; Tan, W. C.; Wang, L.; Dong, B.; Lee, C.; Ang, K. W., Infrared Black Phosphorus Phototransistor with Tunable Responsivity and Low Noise Equivalent Power. ACS Appl. Mater. Interfaces 2017, 9, 36130-36136.

(60)

Clément, N.; Nishiguchi, K.; Fujiwara, A.; Vuillaume, D., One-by-One Trap Activation in Silicon Nanowire Transistors. Nat. Commun. 2010, 1, 92.

(61)

Guo, Q.; Pospischil, A.; Bhuiyan, M.; Jiang, H.; Tian, H.; Farmer, D. B.; Deng, B.; Li, C.; Han, S. J.; Wang, H., Black Phosphorus Mid-Infrared Photodetectors with High Gain. Nano Lett. 2016, 16, 4648.

(62)

Guo, N.; Gong, F.; Liu, J.; Jia, Y.; Zhao, S.; Liao, L.; Su, M.; Fan, Z.; Chen, X.; Lu, W., Hybrid WSe2-In2O3 Phototransistor with Ultrahigh Detectivity by Efficient Suppression of Dark Currents. ACS Appl. Mater. Interfaces 2017, 9, 34489-34496.

(63)

Hwang, I.; Kim, J.; Lee, M.; Lee, M. W.; Kim, H. J.; Kwon, H. I.; Hwang, D. K.; Kim, M.; Yoon, H.; Kim, Y. H.; Park, S. K., Wide-Spectral/Dynamic-Range Skin-Compatible Phototransistors Enabled by Floated Heterojunction Structures with Surface Functionalized Swcnts and Amorphous Oxide Semiconductors. Nanoscale 2017, 9, 16711-16721.

(64)

Noh, Y. Y.; Ghim, J.; Kang, S. J.; Baeg, K. J.; Kim, D. Y.; Yase, K., Effect of Light Irradiation on the Characteristics of Organic Field-Effect Transistors. J. Appl. Phys. 2006, 100, 99.

(65)

Wu, Y. C.; Liu, C. H.; Chen, S. Y.; Shih, F. Y.; Ho, P. H.; Chen, C. W.; Liang, C. T.; Wang, W. H., Extrinsic Origin of Persistent Photoconductivity in Monolayer MoS2 Field Effect Transistors. Sci. Rep. 2015, 5, 11472.

24

ACS Paragon Plus Environment

Page 25 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

ToC graphic

25

ACS Paragon Plus Environment