Photomodulated Hysteresis Behaviors in ... - ACS Publications

Subscriber access provided by CORNELL UNIVERSITY LIBRARY

Article

Photo-Modulated Hysteresis Behaviors in Perovskite Phototransistors with Ultra-Low Operating Voltage Yilin Sun, Changjiu Teng, Dan Xie, Liu Qian, and Mengxing Sun J. Phys. Chem. C, Just Accepted Manuscript • Publication Date (Web): 09 May 2017 Downloaded from http://pubs.acs.org on May 10, 2017

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 free 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 accessible to all readers and 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.

The Journal of Physical Chemistry C 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 21

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

The Journal of Physical Chemistry

Photo-Modulated Hysteresis Behaviors in Perovskite Phototransistors with Ultra-Low Operating Voltage Yilin Sun, †‡ Changjiu Teng, †‡ Dan Xie, *† Liu Qian, § Mengxing Sun† †

Institute of Microelectronics, Tsinghua National Laboratory for Information Science

and Technology (TNList), Tsinghua University, Beijing 100084, People’s Republic of China §

Department of Chemistry, Tsinghua University, Beijing 100084, People’s Republic

of China

Abstract: Hysteresis behaviors in the current curves of perovskite-based devices have been widely observed and directly affect the device performances. In this paper, phototransistors with a channel material of CH3NH3PbI3 were fabricated, and they showed ambipolar transport characteristics with anticlockwise hysteresis hoops. Electric field and monochromatic light can narrow the wide hysteresis window from 2.1 V in the dark to only 0.5 V under the illumination. A photo-excited high field effect carrier mobility of 1.05 cm2V-1s-1 was achieved at a low-operating voltage. The responsivity and photosensitivity of the phototransistor was calculated to be 1 AW-1 and 18000%, respectively. The modulation effect of voltage bias and monochromatic lights on such hysteresis behaviors has been demonstrated. By investigating the photo sensitive carrier transport characteristics in perovskite channel, the origin of hysteresis can be attributed to the charge-trapping process. Besides, this work also provides an effective approach to achieve a photo-controlled temporary erasing process as data protection mechanism in future photomemory devices.

Introduction Methylammonium lead triiodide perovskites (CH3NH3PbX3, X=halogen) have excellent optical and electrical properties.1-3 Thus, they have been extensively 1

ACS Paragon Plus Environment


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 21

explored for fabricating high-performance hybrid solid-state photovoltaic devices such as hybrid organic–inorganic solar cells photodetectors.10-12 Particularly,

perovskites

4-7

, light-emitting diodes

8,9

and

are attractive sensitizers for

photodetectors because of their suitable direct bandgap, large absorption coefficients, ease of solution-based processing and outstanding charge transport properties.13-15 In spite of great development of perovskite-based optoelectronic applications, their intrinsic properties such as the charge transport properties remain elusive, which are essential for optoelectronic devices.16-17 Up to date, the charge transport properties of perovskites were mainly studied by evaluating the performance of photovoltaic devices.16 However, perovskite solar cells usually exhibit hysteresis behaviors in current curves.18 This phenomenon is frequently attributed to iron drift together with the ferroelectric polarization of perovskites and trap-state filling effects.19-21 On the other hand, the study on carrier transport characteristics and electrical hysteresis in field effect transistors (FETs) is still inadequate.16, 22 In recent works, the effects of thermal annealing on the charge transport properties have been investigated.23-24 However, the modulation effects of monochromatic light and electric field on the carrier transport characteristics and current hysteresis in transistor devices have been rarely reported. Herein,

we

reported

the

fabrication

and

characterizations

of

the

CH3NH3PbI3-based FETs. The introduction of a high-k dielectric HfO2 as gate insulators helps to obtain high-performance transistors and achieve a ultra-low operation voltage. The charge transport characteristics and hysteresis behaviors of their current-voltage curves under monochromatic lights and electric fields were studied. Ambipolar nature of charge transport in CH3NH3PbI3-based FETs was observed and an effective photo-modulated hysteresis behavior upon electric field effect has also been achieved with photo-sensitive hysteresis windows. This photo-controlled transient data-erasing process may offer a novel way to realize data-protection and open up new opportunities for the development of photomemory devices. 2


Page 3 of 21

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


Methods The modulation effect of voltage bias and monochromatic lights on the carrier transport characteristics is investigated in the CH3NH3PbI3-based phototransistors (see the 3D schematic in Figure 1a). The bottom-gated FET structure has been adopted here with a highly doped p-type silicon as bottom electrodes and a 20nm-thick HfO2 by ALD process as bottom gate dielectrics. Before perovskite film preparation, the substrate was cleaned as the standard washing process and followed by a UV-ozone treatment. The perovskite CH3NH3PbI3 precursor solution has been prepared as reported in our previous work 25 and spin-coated on the substrate at 4000 rpm for 60 s and heated at 90 °C for 30s. Finally, 50nm-thick Au electrodes were deposited on the perovskite films by electron beam evaporation through a shadow mask. SEM images were carried out on a Sirion-200 field-emission scanning electron microscope (FEI). XRD patterns were taken out by using a D8 Advanced X-ray diffractometer with Cu Kα radiation (Bruker). Absorption spectra were recorded on a Lambda 35 UV-vis spectrometer (Perkin Elmer). PL spectra were performed on a FLSP920 fluorescence spectrometer (Edinburgh). The electrical performance of the phototransistors was studied by using a B1500A Semiconductor Device Analyzer (Agilent Technologies) and Summit 11000 AP probe station (CASCADE microtech) at room temperature. The monochromatic lights with different wavelengths were provided by CEL-LEDS35 LED illuminant (CEAULIGHT).

Results and discussion The scanning electron micrograph (SEM) image of this device is shown in Figure 1b, revealing that the channel of this device has a length of about 100 µm and a width around 300 µm. The top-view SEM image of an as-prepared perovskite film shows the smooth surface without pinholes, consisting of uniform gains with sizes up to hundreds of nanometers (Figure 1c). X-diffraction (XRD) pattern of this film exhibits three strong peaks at 2θ = 14.12°, 29.5° and 43.27°, and they are assigned to (110), (220) and (330) crystal planes of CH3NH3PbI3, respectively (Figure 1d). These results indicate that the halide perovskite film possesses an expected tetragonal crystal 3



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

structure with high crystallinity. Figure 1e shows the light absorption spectrum of CH3NH3PbI3 films, indicating a strong and broad absorption from the ultraviolet to visible-light range. This result reveals that the perovskite is a good light absorber. From the PL spectra of CH3NH3PbI3 films measured with the excitation of a 532 nm laser, it exhibits a red-shifted emission peak at 782 nm, which may originate from the spontaneous radiative recombination between trap states compared with that from the band edge transition. 21, 26

Figure 1 (a) Schematic illustration of a CH3NH3PbI3-based FET. Top view SEM images of a CH3NH3PbI3-based FET unit (b) and a pure CH3NH3PbI3 film (c). XRD patterns (d) and absorption spectra (e) of CH3NH3PbI3 films. (f) PL spectra for pure CH3NH3PbI3 films excitated at 532 nm.

The carrier transport and hysteresis characteristics of CH3NH3PbI3-based FETs were studied by applying a bottom-gate sweeping voltage (VGS) in a closed cycle from −3 to 3 V and then back to −3 V (Figure 2a). This device was measured in the dark at a drain voltage (VDS) of 1 V. The typical ambipolar transport characteristics with both holes and electrons contributing to the drain current can be clearly seen in the drain current versus gate voltage (IDS-VGS) curves. Such V-shaped transfer curves is similar to those reported for ambipolar transistors such as graphene-based transistors.27 Meanwhile, the IDS obtained at the VGS of -3 V (hole conducting region) is above 10−7 A . This current is stronger than that of about 10−8 A at the VGS of 3 V 4


Page 4 of 21

Page 5 of 21

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


(electron conducting region), indicating a stronger p-type behavior in CH3NH3PbI3 films. Besides, another noticeable observation is that hysteresis behaviors appear when VGS is swept under an opposite direction. Despite the still existing ambipolar characteristics, an obvious shift of the location of the minimum current point has been achieved with VGS swept under two opposite direcions. In order to understand the hysteresis behaviors under the electric field effect, this shift has been defined as the hysteresis window (∆VM) shown in Figure 2a and its value was calculated to be about 2.1 V. As discussed above, the origin of the hysteresis in CH3NH3PbI3-based FETs is remaining to be unclear. However, the results here may help to exclude the influence of ferroelectricity in CH3NH3PbI3 films because the direction of the obtained hysteresis is exactly opposite to that of ferroelectric polarization. Figure 2b and 2c show the hysteresis behaviors of our CH3NH3PbI3-based FETs under the modulation of electric field effect with VDS and VGS, respectively. A set of transport curves has been obtained with VDS ranging from 0.1 to 1 V and VGS swept in a closed cycle (Figure 2b). A symmetrical hysteresis loop can be seen at VDS of 0.1 V, which achieves a working state with ultra-low operation voltage. With VDS increasing to a more positive value, both the minimum current points achieved under different VGS sweeping directions shift to the right and the maximum hole current at VGS = -3 V has been found to be stronger than electron current at VGS = 3 V. This shift exhibits an enhanced hole conducting behavior with an increasing VDS, demonstrating the modulation of VDS on the hysteresis behaviors of CH3NH3PbI3 films. The hysteresis behaviors with different VGS sweeping ranges have been shown in Figure 2c, indicating significantly enlarged hysteresis loops when the increase of VGS sweeping range. These results are consistent with the principle of field effect because when VGS increases, the induced carriers by field effect through gate insulators will be also increased, resulting in a large current. Meanwhile, the output characteristics of our device have been investigated with VGS ranging from -2 to 2 V at a step of 1 V and VDS swept from 0 to 1 V in Figure 2d. It can be seen that there is obvious field effect and the current value is consistent with the transport characteristics. 5



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

Figure 2. The ampolar transport curves with hysteresis behaviors. (a) The transport characteristics in a closed sweeping loop with VDS = 1 V. (b) The transport curves with VDS ranging from 0.1 to 1 V. (c) The transfer curves under different VGS sweeping ranges with VDS=0.1 V. (d) The output curves of such FET device with VGS ranging from -2 to 2 V at a step of 1 V.

Our fabricated CH3NH3PbI3-based FETs showed sensitive photoresponse to a monochromatic light with a wavelength of 660 nm and an irradiation power density of 464 µWcm−2. It can be clearly seen from Figure 3a that a shift of hysteresis loop occurred when it was exposed to the illumination and rapidly returned to its original state after the illumination removed. The photo-switching characterisitics with different VGS have been investigated and fast rising and recovery time below 50 ms has been achieved (Figure S1). The hysteresis window under the illumination (∆VML) has been reduced to be 0.5 V, which is much smaller than ∆VM of 2.1 V in the dark. In order to carefully analyze the results, the transport curves have been studied under different VGS sweeping directions. The IDS-VGS curves in the dark and under the 6


Page 6 of 21

Page 7 of 21

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


illumination with the VGS swept from −3 to 3 V (Figure 3b). The minimum current point shifts to the positive voltage direction and IDS in the hole conducting region has increased more than that in the electron conducting region under the illumination. This difference of the photo-generated IDS between hole and electron conducting regions indicates that photo-generated holes play the dominant role in improving the major channel current. Here, two different minimum current points were obtained under two opposite sweeping directions in the dark as shown in Figure 3b and 3d. The reason for this shift of minimum current points may be the migration of defects in such perovskite-based hybird structure.28 As shown in Figure 3c, the photosensitivity defined by (Ilight-IDark)/Idark*100% has been calculated to be about 15,000% at VGS closed to 0 V and the maximum photoresponsivity (R) is found to be about 0.45 AW−1 at VGS of −3 V. The similar observations for the transport curves with VGS swept from 3 to −3 V have been shown in Figure 3d except that the minimum current point only shifts a little to the positive voltage direction. From Figure 3e, the maximum value of photosensitivity is calculated to be about 18,000% at VGS of 1.9 V and the maximum R is to be 0.32 AW−1 at VGS of −2.4 V. Based on these results, a tradeoff may exist between photo-induced variation and R when considering the actual design of photodetectors.

7



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

Figure 3. (a) The hysteresis behaviors observed in CH3NH3PbI3-based FETs in the dark (blue line), under the monochromatic light with a wavelength of 660 nm (orange line) and back in the dark (black line). (b) The transport curves with VGS sweeping from -3 to 3 V. (c) The photosensitivity and responsivity calculated from Figure 3b. (d) The transport curves with VGS sweeping from 3 to -3 V. (e) The photosensitivity and responsivity calculated from Figure 3d.

To further study the hysteresis behaviors under the illumination, the transport curves with VDS ranging from 0.1 to 1 V have been measured. The photo-sensitive hysteresis behaviors show a significant modulation effect of VDS on the photoresponse 8


Page 8 of 21

Page 9 of 21

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


(Figure S2). The ∆VM obtained in the dark and ∆VML under the illumination are plotted as a function of VDS (Figure 4a). The ∆VM in the dark kept nearly unchanged with the increase of VDS, while the ∆VM under the illumination was linearly reduced to be 0.38 V at VDS of 1 V. Meanwhile, the threshold voltages (VTH) of the hole-conducting region with VGS swept from −3 to 3 V in the dark and under the illumination have also been calculated as a function of VDS (inset of Figure 4a). The VTH under the illumination shows a more steep linear relationship with VDS than that in the dark. The VDS-dependence of photo-induced hysteresis behaviors can be explained by the fact that a larger VDS means a stronger drive power through the conducting channel, which can help to accelerate the directional movement of carriers. Moreover, the contribution of the holes are much more dramatic than that of electrons under illumination, resulting in obvious shift of the left minimum drain current point and the little change of the right minimum current point. As a result, the ∆VM defined by the difference between two minimum current points is reduced with the increase of VDS. The reason for this unilateral enhancement of hole current may be attributed to the existence of charge trap states in the perovskite films and the interface between perovskite films and substrate. As known, electron-hole pairs can be generated under the illumination in the pervoskite films. Both two types of carrier may contribute to the current as the perovskite, CH3NH3PbI3, is an ambipolar semiconductor. A much stronger hole-conducting behavior under the illumination indicates a electron-trapping in the carrier transfer process. It is also consistent with the PL results as shown in Figure 1f, which offers the evidence on the existence of trap states. Moreover, it is noted that the electron-trapping process furtherly confirms that the origin of the hysteresis behaviors in perovskite-based phototransistors is from the trap-state filling effects. Besides, the photosensitivity has been also investigated as shown in Figure 4b, indicating that with VGS swept from -3 to 3 V or in reverse, it keeps in a stable value about 10,000% with the increase of VDS. And both current on/off ratios in the dark and under the illumination have been also found to be in the range from 103 to 104. To examine the photo-generated carrier behaviors with the increase of VDS, the field effect carrier mobilities of both holes and electrons have been extracted from the 9



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

transport curves in the dark (Figure 4c) and under the illumination (Figure 4d) and plotted as a function of VDS. From Figure 4c, the hole mobility at VDS of 0.1 V was calculated to be 0.53 cm2V−1s−1 in the dark and then elevated to be 1.05 cm2V−1s−1 under the illumination. When VDS was fixed at other values, and the hole mobilities under the illumination all exhibit an increasing trend compared with that in the dark. While from Figure 4d, the electron mobilities show a little change before and after the illumination and with the increase of VDS, the electron mobility is distinctly lower than the hole mobility. The discussion about the mobilities could offer some clues: First, illumination motivates more hole-conducting behaviors, which is consistent with the results shown in Figure 3; Second, all the mobilities obtained in the dark and under the illumination is degraded with the increase of VDS, especially for the electron mobility. Finally, the high field effect mobilities reported in this work may benefit from the introduction of high-k dielectrics, HfO2.

Figure 4. (a) The ∆VM and ∆VML is plotted as a function of VDS. The inset is the curve of VTH versus VDS. (b) The plot of photosensitivity versus VDS in different VGS 10


Page 10 of 21

Page 11 of 21

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


sweeping directions. The inset is the plot of Ion/Ioff versus VDS. The plot of hole carrier mobility (c) and electron carrier mobility (d) versus VDS, respectively.

Another important issue is that how the illumination with different irradiation power

and

wavelengths

affect

these

obtained

hysteresis

behaviors

in

CH3NH3PbI3-based FETs. In Figure 5a, hysteresis behaviors show sensitive photoresponse with the irradiation power from 62 to 464 µWcm-2. As shown in Figure 5b, the ∆VM obviously decreases with the increase of the irradiance due to an enhanced hole-conducting behaviors, which demonstrates the modulation of irradiance on these hysteresis behaviors. Maximum photocurrent and responsivity are measured to be about 25 nA under 464 µWcm-2 and 1 AW-1 under 62 µWcm-2, respectively (Figure 5c). Upon the illumination by a monochromatic light with a wavelength of 470, 590, 660 or 850 nm , the hysteresis behaviors display the similar sensitive photoresponse to the visible light region (Vis, 470~660 nm) with smaller ∆VM

and maximum responsivity of 1.14 AW-1 (660nm) and a relatively weak

photoresponse to the near-infrared (NIR) region (850 nm) with larger ∆VM and responsivity of 0.08 AW-1 at the same irradiance (Figure 5d, e, f). The results demonstrate the modulation effect of monochromatic light from Vis to NIR region on the hysteresis behaviors in CH3NH3PbI3-based FETs. Based on these results, a circuit model has been set up to illustrate the photo-controlled data-protection mechanism by transient data-erasing process (Figure S3 and S4). This conception on transient data-erasing process may open up an unique vision for the development of theory and applications for information security.

11



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 21

Figure 5. (a) The hysteresis behaviors under different irradiance power when a monochromatic light with a wavelength of 660 nm applied. (b) Plot of ∆VM versus irradiance. (c) Plot of photocurrent and responsivity versus irradiance under the illumination of 660 nm with VDS=1 V. (d) The hysteresis behaviors with different wavelengths of 470 nm, 590 nm, 660 nm and 850 nm. An average irradiance for these different wavelengths measured by a power meter is 77 µWcm-2. (e) Plot of ∆VM versus wavelength. (f) Plot of photocurrent and responsivity versus wavelength.

Conclusions In conclusion, a bottom-gated FET structure based on CH3NH3PbI3 channel via a low-cost solution processing strategy and high-k HfO2 dielectric by ALD deposition has been fabricated. Remarkable hysteresis behaviors obtained in the transfer characteristics of CH3NH3PbI3-based FETs can be modulated by external voltages under the field effect. Operating at a low voltage, the hysteresis behaviors in CH3NH3PbI3-based FET

structure

exhibit

sensitive

photo

responsivity

to

monochromatic light, which contributes to a significant improvement of the device performances such as hole carrier mobility up to 1.05 cm2V-1s-1. Meanwhile, the modulation of monochromatic light from Vis to NIR region on such hysteresis behaviors has been demonstrated, which may open up a new sight in future photomemory devices. This work inspires the understanding and development on perovskite-based FETs for cheap and high-performance large scale intergrated 12


Page 13 of 21

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


optoelectronics. It can be inferred that these findings will offer a better understanding of electrical and optical properties of perovskite and contribute to the development of the perovskite-based electronic devices.

Associated Content Supporting Information Photo-switching characteristics of such phototransistors, the hysteresis behaviors observed in the transfer characteristics of CH3NH3PbI3-based FETs under different VDS, the schematic of a light-controlled data protection circuit and the potential principle of operation for this transient data-erasing process. Author Information Corresponding Author *Email：[email protected] Author Contributions The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript. ‡These authors contributed equally.

Notes The authors declare no competing financial interest.

Acknowledgements The authors are grateful for the financial support from National Natural Science Foundation of China (No. 51672154 and 51372130), the MoST (2016YFA0200200), Open Research Fund Program of the State Key Laboratory of Low-Dimensional Quantum Physics (No. KF201517).

References

13



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

1. Green, M. A.; Ho-Baillie, A.; Snaith, H. J. The emergence of perovskite solar cells. Nat. Photon 2014, 8, 506-514. 2. Xing, G.; Mathews, N.; Sun, S.; Lim, S. S.; Lam, Y. M.; Grätzel, M.; Mhaisalkar, S.; Sum, T. C. Long-range balanced electron-and hole-transport lengths in organic-inorganic CH3NH3PbI3. Science 2013, 342, 344-347. 3. Gao, P.; Gratzel, M.; Nazeeruddin, M. K. Organohalide lead perovskites for photovoltaic applications. Energ. Environ. Sci. 2014, 7, 2448-2463. 4. Lee, M. M.; Teuscher, J.; Miyasaka, T.; Murakami, T. N.; Snaith, H. J. Efficient hybrid solar cells based on meso-superstructured organometal halide perovskites. Science, 2012, 338, 643-647. 5. Liu, M.; Johnston, M. B.; Snaith, H. J. Efficient planar heterojunction perovskite solar cells by vapour deposition. Nature, 2013, 501, 395-398. 6. Gong, X.; Li, M.; Shi, X. B.; Ma, H.; Wang, Z. K.; Liao, L. S. Controllable perovskite crystallization by water additive for high‐performance solar cells, Adv. Funct. Mater. 2015, 25, 6671-6678. 7. Wang, Z. K.; Li, M.; Yuan, D. X.; Shi, X. B.; Ma, H.; Liao, L. S. Improved hole interfacial layer for planar perovskite solar cells with efficiency exceeding 15%, ACS Appl. Mater. Inter. 2015, 7, 9645-9651.. 8. Hoye R. L. Z.; Chua M. R.; Musselman K. P.; G. Li; Lai, M. L.; Tan, Z. K.; Greenham, N. C.; MacManus-Driscoll, J. L.; Friend, R. H.; Credgington, D. Enhanced performance in fluorene ‐ free organometal halide perovskite light-emitting diodes using tunable low electron affinity oxide electron injectors. Adv. Mater. 2015, 27, 1414-1419. 9. Tan Z. K.; Moghaddam, R. S.; Lai, M. L.; Docampo, P.; Higler, R.; Deschler, F.; Price, M.; Sadhanala, A.; Pazos, L. M.; Credgington D. et al. Bright light-emitting diodes based on organometal halide perovskite. Nat. Nano. 2014, 9, 687-692. 10. Dou, L.; Yang, Y.; You, J.; Hong, Z.; Chang, W.-H.; Li, G.; Yang, Y. Solution-processed hybrid perovskite photodetectors with high detectivity. Nat. Commun. 2014, 5, 5404. 11. Hu, X.; Zhang, X.; Liang, L.; Bao, J.; Li, S.; Yang, W.; Xie, Y. High‐performance flexible broadband photodetector based on organolead halide perovskite. Adv. Funct. Mater. 2014, 24, 7373-7380. 14


Page 14 of 21

Page 15 of 21

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


12. Lee, Y.; Kwon, J.; Hwang, E.; Ra, C.-H.; Yoo, W. J.; Ahn, J.-H.; Park, J. H.; Cho, J. H. High ‐ performance perovskite – graphene hybrid photodetector. Adv. Mater. 2015, 27, 41-46. 13. Giorgi, G.; Fujisawa, J. -I.; Segawa, H.; Yamashita, K. Small photocarrier effective masses featuring ambipolar transport in methylammonium lead iodide perovskite: a density functional analysis. J. Phys. Chem. Lett. 2013, 4, 4213-4216. 14. Wehrenfennig, C.; Eperon, G. E.; Johnston, M. B.; Snaith, H. J.; Herz, L. M. High charge carrier mobilities and lifetimes in organolead trihalide perovskites. Adv. Mater. 2014, 26, 1584-1589. 15. PonsecaJr, C. S.; Savenije, T. J.; Abdellah, M.; Zheng, K .; Yartsev, A.; Pascher, T.; Harlang, T.; Chabera, P.; Pullerits, T.; Stepanov, A. et al. Organometal halide perovskite solar cell materials rationalized: ultrafast charge generation, high and microsecond-long balanced mobilities, and slow recombination, J. Am. Chem. Soc. 2014, 136, 5189-5192. 16. Chin, X. Y.; Cortecchia, D.; Yin, J.; Bruno, A.; Soci, C. Lead iodide perovskite light-emitting field-effect transistor. Nat. Commun. 2015, 6. 7383. 17. Mei, Y.; Zhang, C.; Vardeny, Z. V.; Jurchescu, O. D. Electrostatic gating of hybrid halide perovskite field-effect transistors: balanced ambipolar transport at room-temperature. MRS Communications, 2015, 5, 297-301. 18 Snaith, H. J.; Abate, A.; Ball, J. M.; Eperon, G . E.; Leijtens, T.; Noel, N. K.; Stranks, S. D.; Wang, J. T-Wei; Wojciechowski, K.; Zhang, W. Anomalous hysteresis in perovskite solar cells. J. Phys. Chem. Lett. 2014, 5, 1511-1515. 19. Xiao, Z.; Yuan, Y.; Shao, Y.; Wang, Q.; Dong, Q.; Bi, C.; Sharma, P.; Gruverman, A.; Huang, J. Giant switchable photovoltaic effect in organometal trihalide perovskite devices. Nat. Materials 2015, 14, 193-198. 20. Frost, J. M.; Butler, K. T.; Walsh, A. Molecular ferroelectric contributions to anomalous hysteresis in hybrid perovskite solar cells. APL Mater. 2014, 2, 081506. 21. Shao, Y.; Xiao, Z.; Bi, C.; Yuan, Y.; Huang, J. Origin and elimination of photocurrent hysteresis by fullerene passivation in CH3NH3PbI3 planar heterojunction solar cells, Nat. Commun. 2014, 5, 5784. 22. Li, F.; Ma, C.; Wang, H.; Hu, W.; Yu, W.; Sheikh, A. D.; Wu, T. Ambipolar solution-processed hybrid perovskite phototransistors. Nat. Commun. 2015, 6, 8238. 15



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

23. Li, D.; Cheng, H. C.; Wang, Y.; Zhao, Z.; Wang, G.; Wu, H.; He, Q.; Huang, Y.; Duan, X. The effect of thermal annealing on charge transport in organolead halide perovskite microplate field ‐ effect transistors. Advanced Materials, 2017, 29, 1601959. 24. Li, D.; Cheng, H. C.; Wu, H.; Wang, Y.; Guo, J.; Wang, G.; Huang, Y.; Duan, X. Gate-induced insulator to band-like transport transition in organolead halide perovskite. The Journal of Physical Chemistry Letters, 2016, 8, 429-434. 25. Chen, S.; Teng, C.; Zhang, M.; Li, Y.; Xie, D.; Shi, G. A flexible UV-Vis-NIR photodetector based on perovskite/conjugated polymer composite. Adv. Mater. 2016, 28, 5969-5974 26. Ma, C.; Shi, Y.; Hu, W.; Chiu, M. H.; Liu, Z.; Bera, A.; Li, F.; Wang, H.; Li, L. J.; Wu, T. Heterostructured WS2/CH3NH3PbI3 photoconductors with suppressed dark current and enhanced photodetectivity. Adv. Mater. 2016, 28, 3683-3689. 27. Feng T.; Xie D.; Zhao, H.; Li, G.; Xu, J.; Ren, T.; Zhu, H. Ambipolar/unipolar conversion in graphene transistors by surface doping. Appl. Phys. Lett. 2013, 103, 193052. 28. Kwon, K. C.; Hong, K.; Van Le, Q.; Lee, S. Y.; Choi, J.; Kim, K. B.; Kim, S. Y.; Jang, H. W. Inhibition of ion migration for reliable operation of organolead halide perovskite‐based metal/semiconductor/metal broadband photodetectors. Adv. Funct. Mater. 2016, 26, 4213-4222. . TOC Graphic

16


Page 16 of 21

Page 17 of 21

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


Figure 1 (a) Schematic illustration of a CH3NH3PbI3-based FET. Top view SEM images of a CH3NH3PbI3based FET unit (b) and a pure CH3NH3PbI3 film (c). XRD patterns (d) and absorption spectra (e) of CH3NH3PbI3 films. (f) PL spectra for pure CH3NH3PbI3 films excitated at 532 nm. 72x38mm (300 x 300 DPI)



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

Figure 2. The ampolar transport curves with hysteresis behaviors. (a) The transport characteristics in a closed sweeping loop with VDS = 1 V. (b) The transport curves with VDS ranging from 0.1 to 1 V. (c) The transfer curves under different VGS sweeping ranges with VDS=0.1 V. (d) The output curves of such FET device with VGS ranging from -2 to 2 V at a step of 1 V.


Page 18 of 21

Page 19 of 21

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


Figure 3. (a) The hysteresis behaviors observed in CH3NH3PbI3-based FETs in the dark (blue line), under the monochromatic light with a wavelength of 660 nm (orange line) and back in the dark (black line). (b) The transport curves with VGS sweeping from -3 to 3 V. (c) The photosensivity and responsivity calculated from Figure 3b. (d) The transport curves with VGS sweeping from 3 to -3 V. (e) The photosensivity and responsivity calculated from Figure 3d. 65x132mm (300 x 300 DPI)



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

Figure 4. (a) The ∆VM and ∆VML is plotted as a function of VDS. The inset is the curve of VTH versus VDS. (b) The plot of photosensivity versus VDS in different VGS sweeping directions. The inset is the plot of Ion/Ioff versus VDS. The plot of hole carrier mobility (c) and electron carrier mobility (d) versus VDS, respectively.


Page 20 of 21

Page 21 of 21

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


Figure 5. (a) The hysteresis behaviors under different irradiance power when a monochromatic light with a wavelength of 660 nm applied. (b) Plot of ∆VM versus irradiance. (c) Plot of photocurrent and responsivity versus irradiance under the illumination of 660 nm with VDS=1 V. (d) The hysteresis behaviors with different wavelengths of 470 nm, 590 nm, 660 nm and 850 nm. An average irradiance for these different wavelengths measured by a power meter is 77 µWcm-2. (e) Plot of ∆VM versus wavelength. (f) Plot of photocurrent and responsivity versus wavelength. 67x34mm (300 x 300 DPI)


Photomodulated Hysteresis Behaviors in ... - ACS Publications

Recommend Documents