Bright Orange Electroluminescence from Lead-Free Two-Dimensional

Subscriber access provided by Columbia University Libraries

Letter

Bright Orange Electroluminescence from Lead-Free Two-Dimensional Perovskites Xiangtong Zhang, Congcong Wang, Yu Zhang, Xiaoyu Zhang, Shixun Wang, Min Lu, Haining Cui, Stephen V Kershaw, William W. Yu, and Andrey L. Rogach ACS Energy Lett., Just Accepted Manuscript • DOI: 10.1021/acsenergylett.8b02239 • Publication Date (Web): 11 Dec 2018 Downloaded from http://pubs.acs.org on December 12, 2018

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 23 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 Energy Letters

Bright

Orange

Electroluminescence

from

Lead-Free

Two-Dimensional Perovskites Xiangtong Zhang,†,# Congcong Wang,‡,# Yu Zhang,*,† Xiaoyu Zhang,† Shixun Wang,† Min Lu,† Haining Cui,‡ Stephen V. Kershaw,§ William W. Yu,†,|| and Andrey L. Rogach*,§,⁋

†State

Key Laboratory of Integrated Optoelectronics and College of Electronic Science and

Engineering, Jilin University, Changchun, 130012, China ‡College

of Physics, Jilin University, Changchun 130012, China

§Department

of Materials Science and Engineering and Centre for Functional Photonics, City

University of Hong Kong, Hong Kong SAR ||Department

of Chemistry and Physics, Louisiana State University, Shreveport, LA 71115,

USA ⁋Beijing

Institute of Technology, School of Materials Science and Engineering, Beijing

100081, China

Corresponding Authors * (Y.Z.) [email protected]. * (A.L.R) [email protected].

1

ACS Paragon Plus Environment

ACS Energy Letters 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 23

Abstract Lead halide perovskites are important materials for solar cells and light emitting diodes (LEDs), but the toxicity of lead is a matter of concern for these and other commercial applications.

Here,

we

demonstrate

a

lead-free

two-dimensional

(2D)

Ruddlesden-Popper-type (C18H35NH3)2SnBr4 perovskite with a strong emission from the self-trapped states, whose photoluminescence quantum yields in colloidal suspension and in film are 88% and 68%, respectively. The insulating character of the organic oleylamine cation prevents electronic band formation between the [SnBr6]4- octahedron layers, which results in the Stokes-shifted orange emission. Electroluminescence of these 2D lead-free perovskite materials was demonstrated in an inverted LED structure with a low turn-on voltage of 2.2 V and a luminance of 350 cd/m2.

TOC Graphic

2


Page 3 of 23 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 Energy Letters

Introduction Lead halide perovskites (LHPs) offer a great potential to develop inexpensive, efficient, bright, and large-area light-emitting devices (LEDs) and color displays.1-3 With widely tunable emission wavelengths (410700 nm), narrow emission (full width at half maximum (FWHM) in a rage of 1225 nm), and photoluminescence quantum yields (PL QYs) reaching 90% and even higher,4-7 LHPs may allow for the production of the most color-saturated blue, green and red LEDs outperforming organic LEDs and other LEDs. The brightness of LHP-based LEDs has been dramatically improved in recent years, reaching tens of thousands candelas per square meter, and the external quantum efficiency (EQE) has exceeded 10%,8-11 making these materials suitable for commercial markets. At the same time, a serious drawback of the up-to-date LHP-LEDs is the presence of toxic lead in the highly-performing perovskites, which severely hinders their practical exploitation. There have been immense efforts to replace Pb with non-toxic elements in different kinds of perovskites, namely those with the three-, two-, one-, and zero-dimensional (3D, 2D, 1D, 0D) structures. For 3D perovskites, the most obvious alternative substitution to Pb2+, namely Sn2+, as well as combinations of monovalent (Ag+, In+, Cu+) and trivalent (In3+, Sb3+, Bi3+) cations have been attempted. Unfortunately, most of the resulting materials exhibit poor stability and low PL QYs, and some of them are also found to bear too large or indirect band gaps.12-14 Though a series of low-dimensional Sn-based and Sb-based perovskites,15-17 as well as Sb-based and Bi-based 2D perovskites18, 19 with much higher PL QYs have been reported, they have rarely been used to produce electroluminescent LEDs. Herein, we report the realization of electroluminescent devices based on a strong 3



Page 4 of 23

emitting lead-free 2D perovskite, namely a (C18H35NH3)2SnBr4 material. Similar with the highly efficient 0D perovskites,15-17,

20

the insulating character of the organic oleylamine

cation (C18H35NH3+, OAm+) prevents electronic band formation between the [SnBr6]4octahedron layers, which results in strongly Stokes-shifted orange emission from the 2D (OAm)2SnBr4 perovskite. The emission is ascribed to the intrinsic self-trapped states of molecular [SnBr6]4- species, and is by far superior to the performance of previously reported 2D analogues.21 We note that Haque et al. have recently reported a red electroluminescent LED based on 2D Sn-based perovskites employing other (phenylethylammonium) organic cation, with a luminance of 0.15 cd/m2, and an efficacy of 0.029 cd/A.22 Our (OAm)2SnBr4-based orange LEDs reach a maximum luminance of 350 cd/m2, and an EQE of 0.1%,

which

constitutes

significant

improvement

on

the

way

to

bright

and

environment-friendly perovskite-based lead-free LEDs suitable for practical applications in solid state lighting.

Results and Discussion The synthesis of the (OAm)2SnBr4 perovskite was conducted in solution by a hot injection method, as outlined in the Experimental Section. The transmission electron microscopy (TEM) image in Figure 1a illustrates that the (OAm)2SnBr4 microplates have large lateral dimensions and tend to stack over each other vertically, as illustrated by the schematic drawing. The interplanar spacing of the crystalline structure observed in the high resolution TEM images is 3.2 Å (Figure 1b), which corresponds to the diffraction peak at 28.3° (marked with *) in the X-ray diffraction (XRD) pattern given in Figure 1c. Between 12 4


Page 5 of 23 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 Energy Letters

to 30 degrees, the XRD peaks are located at 14.1°, 16.4°, 18.8°, 21.2°, 23.6°, 25.9° and 28.3°, respectively. XRD also reveals a periodic diffraction pattern (00l) at low angles with a regular interval of 2.3°, due to the periodic 2D structure of the (OAm)2SnBr4 perovskite, similar to the Pb-based 2D perovskites.23-26 The Fourier-transform infrared (FTIR) spectrum of the (OAm)2SnBr4 perovskite is compared to the FTIR spectra of all of the reactants used in the synthesis (Figure 1d). All of the characteristic peaks of OAm belonging to the basic carbon chain structure (at 1250-1750 cm-1, and 2750-3000 cm-1) appear in the FTIR spectrum of perovskite. The N-H stretch vibration (3348 cm-1) of OAm marked by two red dashed circles moves to 3117 cm-1, which can be attributed to the association between the NH3+ moiety and the [SnBr6]4- octahedron.27 The peak at 3006 cm-1 marked by the green dashed rectangle belongs to the bending vibration of a C-H bond adjacent to a C=C bond; the peaks at 2852 cm-1 and 2922 cm-1 originate from the symmetric and asymmetric C-H stretching vibrations, respectively.28 Three peaks highlighted with 3 green dashed lines originate from the C=C and CH3 bending modes of OAm constituent groups.29 Consequently, we can confirm that OAm+ cations are the main organic component of our 2D perovskite.

5



Page 6 of 23

Figure 1. (a) TEM and (b) HRTEM images, and (c) XRD pattern of (OAm)2SnBr4 perovskite. (d) FTIR spectra of (OAm)2SnBr4 perovskite and all of the reactants used in its synthesis. Schematic drawing in (a) illustrates multiple microplates stacked over each other in a vertical direction.

6


Page 7 of 23 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 Energy Letters

Figure 2. (a-c) XPS spectra of N, Sn, Br elements in (OAm)2SnBr4 perovskite. (d) Schematic drawing of the 2D structure of the Ruddlesden-Popper-type (OAm)2SnBr4 perovskite.

X-ray photoelectron spectroscopy (XPS) data collected from the 2D perovskite solution drop-cast on a Si substrate are presented in Figure 2(a-c). In Figure 2a, the peak at 401.4 eV originates from the N 1s state; in Figure 2b, two peaks located at 487.0 and 495.5 eV are attributed to the 3d5 state of Sn2+ ions;30 in Figure 2c, two peaks located at 67.7 and 68.7 eV originate from the Br 3d state. The elemental ratio of N:Sn:Br has been determined as 4:1:4.5 from the integrated peak intensities. The total amount of the detected nitrogen originates from the OAm molecules within the perovskite structure and the organic protective shell around.21 The anticipated structure of the (OAm)2SnBr4 2D perovskite is shown in Figure 2d. The periodic spacing d between the centers of mass of the [SnBr6]4- octahedron layers has been 7



Page 8 of 23

determined as 3.8 nm, being calculated considering the regular intervals between the diffraction peaks at a small angle, namely the 2-theta of 2.3° increment. Both the size of the [SnBr6]4- octahedra and the chain length of OAm contribute to this spacing, according to the schematic drawing shown in Figure 2d. The NH3+ heads from OAm+ electrostatically interact with Br- ions in the [SnBr6]4- octahedra, and the long carbon chains interdigitate between the inorganic layers formed by [SnBr6]4- octahedra through the van der Waals interactions in an overlapping tail-tail arrangement.31 The relationship between the layer spacing d and the carbon chain length in OAm is given by an equation d(nm) = 0.85+0.16×n, where n stands for the number of carbon atoms in the carbon chain, according to a previous study on the Pb-based 2D perovskites.32 For the (OAm)2SnBr4 2D perovskite, when n = 18, the value of d is calculated to be 3.7 nm, which is in good agreement with the above mentioned experimental value.

8


Page 9 of 23 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 Energy Letters

Figure 3. (a) Photograph of the colloidal suspension and film of (OAm)2SnBr4 perovskites under UV light. (b) Normalized absorption (Abs), PL excitation (PLE, monitored at 620 nm) and PL (excited by 365 nm) spectra of (OAm)2SnBr4 perovskite film. Temperature dependent time-resolved PL decay curves fitted by a bi-exponential function (c) and normalized emission spectra (d), FWHM and peak position curves (e) of (OAm)2SnBr4 perovskite film. (f) Configuration coordinate diagram for the potential energy curves to illustrate the photophysical processes resulting in emission from the exciton self-trapping state at room temperature.

Under UV light, the colloidal suspension (solution) and film of (OAm)2SnBr4 9



Page 10 of 23

perovskites shine extremely bright orange emission (Figure 3a). Figure 3b shows optical spectra of the (OAm)2SnBr4 2D perovskite film. The broad orange emission is located at 620 nm with a FWHM of 140 nm under excitation of 365 nm. The Stokes shift between the PLE and PL maxima is relatively large, namely 307 nm. Generally, such large Stokes shifts and the broad emission do not originate from direct band related recombination of carriers. Similar to the previously reported 0D, 1D, and corrugated-2D metal halide perovskites and SnBr2 crystals,19, 33, 34 exciton self-trapping may prevail in our (OAm)2SnBr4 2D perovskite materials under the strong quantum confinement. The excitation spectra monitored at 620 nm do not exhibit sub-gap contributions to the PL that may indicate recombination generated from defect related traps, supporting the assignment of self-trapped excitons as the basis for the observed large Stokes shift.35 The temperature dependent PL decay time (Figure 3c) and emission spectra (Figure 3d) offer further evidences for the existence of self-trapped state because of its thermally activated nature.36 Figure 3c shows that the PL decay time of orange emission gradually shortens to 2.18 μs at 77 K from 3.36 μs at 350 K. The observed long PL decay time suggest that the emission from the self-trapped states is phosphorescence lined with many metal complexes and low-dimensional perovskites.21,

37

The PL peak position gradually shifts to

shorter wavelength and its FWHM decreases (Figures 3d and 3e) with lowering the temperature. Simultaneously, the emission intensity of the (OAm)2SnBr4 2D perovskite films first increases upon transition from 77 to 250 K, and then decreases upon further increasing the temperature to 350 K (Figure S1). Parameters of the temperature dependent emission spectra and PL decay times are listed in Table S1. 10


Page 11 of 23 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 Energy Letters

In the classic solid-state theory, the configuration coordinate diagram such as presented in Figure 3f is commonly used to illustrate the photophysical processes resulting in an emission from the exciton self-trapping state.38 Under high energy photon excitation, electrons are excited to a manifold of excited states from the ground state, and in turn fall into lower energy self-trapped states through ultrafast excited state structural reorganization. The subsequent recombination between electrons and holes generates strong Stokes shifts and broadband emissions with microseconds decay time.20, 21, 39 The absolute PL QYs (excited at 365 nm) of the orange emission from the 2D (OAm)2SnBr4 perovskite colloidal suspension and films have been measured to be 88% and 68% using an integrating sphere. Such PL QYs are among the highest in 2D lead-free perovskites reported so far,21,

40-42

rendering (OAm)2SnBr4 2D perovskites promise for

optoelectronic applications. As already discussed above, it is attributed to the quantum confinement effect provided by the periodically arrayed insulating OAm+ cations with long carbon chains, which effectively eliminate electronic band formation between the [SnBr6]4octahedron single layers forming the quantum well-like structure.17, 21 Figure S2 shows that the emission intensity of the (OAm)2SnBr4 2D perovskite powder after storage in air for 10 days still remains at 67% of its initial value, which is much better than that of the 3D Sn-based perovskites that only survives for about 20 min in open air.43 This can be attributed to the rather efficient protection of the outer OAm organic shell.21

11



Page 12 of 23

Figure 4. (a) UPS spectra of (OAm)2SnBr4 perovskite film on an ITO glass substrate. EF: Fermi level. (b) Energy band diagram of the inverted LED structure based on (OAm)2SnBr4 perovskite. (c) Current density (black) and brightness (red) of the LED vs. the driving voltage. (d) EQE of the LED vs. the current density (inset: photograph of an operating LED). (e) PL spectrum (red) of (OAm)2SnBr4 perovskite in solution, and EL spectrum (black) of the LED. (f) Normalized PL spectra of (OAm)2SnBr4 2D perovskite films measured in a temperature range between 20°C and 80°C.

The lead-free nature and the promising luminescence properties of the (OAm)2SnBr4 2D perovskite motivated us to explore its application in charge injection LEDs. Figure 4a provides the ultraviolet photoelectron spectroscopy (UPS) spectra taken from the 12


Page 13 of 23 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 Energy Letters

(OAm)2SnBr4 2D perovskite film. The Fermi energy level, EF (-3.7 eV), and the valence band maximum (VBM, -5.4 eV) are determined from the cutoff and valence region, respectively. The energy level of the self-trapped state (-3.4 eV) is determined from the PL spectrum for our device, and allows us to use an inverted multilayer LED structure.44 Such an LED structure, shown in Figure 4b, consists, from bottom to top, of patterned ITO-coated glass as a cathode, ZnO nanocrystal/polyethylenimine (PEI) bilayer as an electron-transporting layer (ETL),

(OAm)2SnBr4

2D

perovskite

film

as

an

emitting

layer,

4,4,4″-tris(carbazol-9-yl)triphenylamine (TCTA) as a hole-transporting layer (HTL), and MoO3/Au as a anode. ZnO nanocrystals have been synthesized as previously reported.45 The wide bandgap ZnO nanocrystal film was chosen as an ETL and at the same time served as a hole blocking layer (HBL) because of its high electron mobility, excellent optical transparency, and the deep-lying VBM (−7.2 eV).44 The TCTA film was chosen as the HTL and at the same time served as an electron blocking layer (EBL) because of its suitable highest occupied molecular orbital (HOMO, −5.7 eV) and low electron affinity (−2.3 eV).46 The combination of ZnO HBL and TCTA EBL sandwiched the (OAm)2SnBr4 emitting layer allowed for efficient confinement of injected charge carriers, and thus for efficient recombination. The PEI interlayer not only lowered the work function of the cathode contacts but also helped maintain a balanced charge neutrality of the (OAm)2SnBr4 2D perovskite emitters, thus preserving their superior emissive properties.44 The current density-luminance-voltage (J-L-V) curve of the inverted LEDs with (OAm)2SnBr4 2D perovskite as the emitting layer is plotted in Figure 4c. The devices exhibited a high current density of 844 mA/cm2 at the maximum luminance, indicating the 13



Page 14 of 23

easy injection of charge carriers. The low turn-on voltage of 2.2 V implies that charges are directly injected into the self-trapped states, which also corresponds to the energy gap between the self-trapped states and the VBM. The maximum luminance and the EQE (Figure 4d) of the devices were 350 cd/m2 and 0.1%, respectively. The performance of LEDs was listed in Table S2. The EL peak was at 625 nm. Compared with the PL peak of the (OAm)2SnBr4 perovskite film, the FWHM of the EL peak broadened to 162 nm (Figure 4e) probably triggered by heating during operation,47-49 which may be attributed to the thermally activated nature of self-trapped excitons.38, This was confirmed by monitoring the PL spectra of the (OAm)2SnBr4 2D perovskite film at different temperatures (Figure 4f): upon increasing the temperature (from 20°C to 80°C), the FWHM of the PL peaks increased to 140 nm, 147 nm, 155 nm and 162 nm, accompanied by a progressive red shift.

Conclusions In summary, we synthesized lead-free (OAm)2SnBr4 2D perovskite crystals by a facile solution based hot injection method. The confinement in the quantum wells of [SnBr6]4octahedra efficiently separated by insulating layers of OAm+ cations resulted in the high PL QYs of 88% and 68% for the (OAm)2SnBr4 colloidal suspension and film, respectively. We successfully demonstrated EL by using the (OAm)2SnBr4 2D perovskite as an emitting layer in inverted LED structures. The low turn-on voltage of 2.2 V and the maximum luminance of 350 cd/m2 were observed, which is thus far, to the best of our knowledge, the highest brightness reported among the lead-free perovskite LEDs. Even so, further efforts are required to improve the device performance. 14


Page 15 of 23 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 Energy Letters

Supporting Information The Supporting Information is available free of charge on the ACS Publications website at DOI: XXXX Some descriptions of the material and LEDs included in the SI. AUTHOR INFORMATION Corresponding Authors * (Y.Z.) [email protected]. * (A.L.R) [email protected]. Author Contributions #These

authors contributed equally to this work.

Notes The authors declare no competing financial interest.

Acknowledgments This work was supported by the National Natural Science Foundation of China (61675086, 61475062, 61722504, 51772123, 51702115), the National Key Research and Development Program of China (2017YFB0403601), BORSF Professorship, the Institutional Development Award (P20GM103424), the Special Project of the Province-University Co-constructing Program of Jilin University (SXGJXX2017-3), the Research Grants Council of Hong Kong S.A.R. (CityU11337616), the Talent Introduction Plan of Overseas Top Ranking Professors by the State Administration of Foreign Expert Affairs (MSBJLG040), and the Open Research

15



Page 16 of 23

Fund of State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences.

References (1)

Kovalenko, M. V.; Protesescu, L.; Bodnarchuk, M. I. Properties and Potential Optoelectronic Applications of Lead Halide Perovskite Nanocrystals. Science 2017, 358, (6364), 745-750.

(2)

Li, X.; Wu, Y.; Zhang, S.; Cai, B.; Gu, Y.; Song, J.; Zeng, H. CsPbX3 Quantum Dots for Lighting and Displays: Room-Temperature Synthesis, Photoluminescence Superiorities, Underlying Origins and White Light-Emitting Diodes. Adv. Funct. Mater 2016, 26, (15), 2435-2445.

(3)

Kim, Y.-H.; Wolf, C.; Kim, Y.-T.; Cho, H.; Kwon, W.; Do, S.; Sadhanala, A.; Park, C. G.; Rhee, S.-W.; Im, S. H.; et al. Highly Efficient Light-Emitting Diodes of Colloidal Metal–Halide Perovskite Nanocrystals beyond Quantum Size. ACS Nano 2017, 11, (7), 6586-6593.

(4)

Protesescu, L.; Yakunin, S.; Bodnarchuk, M. I.; Krieg, F.; Caputo, R.; Hendon, C. H.; Yang, R. X.; Walsh, A.; Kovalenko, M. V. Nanocrystals of Cesium Lead Halide Perovskites (CsPbX3, X = Cl, Br, and I): Novel Optoelectronic Materials Showing Bright Emission with Wide Color Gamut. Nano Lett 2015, 15, (6), 3692-3696.

(5)

Wang, S.; Bi, C.; Yuan, J.; Zhang, L.; Tian, J. Original Core–Shell Structure of Cubic CsPbBr3@Amorphous CsPbBrx Perovskite Quantum Dots with a High Blue Photoluminescence Quantum Yield of over 80%. ACS Energy Lett 2018, 3, (1), 16


Page 17 of 23 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 Energy Letters

245-251. (6)

Huang, H.; Susha, A. S.; Kershaw, S. V.; Hung, T. F.; Rogach, A. L. Control of Emission Color of High Quantum Yield CH3NH3PbBr3 Perovskite Quantum Dots by Precipitation Temperature. Adv. Sci. 2015, 2, (9), 1500194.

(7)

Kim, Y.-H.; Wolf, C.; Kim, H.; Lee, T.-W. Charge Carrier Recombination and Ion Migration in Metal-Halide Perovskite Nanoparticle Films for Efficient Light-Emitting Diodes. Nano Energy 2018, 52, 329-335.

(8)

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

(9)

Wang, N.; Cheng, L.; Ge, R.; Zhang, S.; Miao, Y.; Zou, W.; Yi, C.; Sun, Y.; Cao, Y.; Yang, R.; et al. Perovskite Light-Emitting Diodes Based on Solution-Processed Self-Organized Multiple Quantum Wells. Nat. Photonics 2016, 10, 699-704.

(10) Lu, M.; Zhang, X.; Bai, X.; Wu, H.; Shen, X.; Zhang, Y.; Zhang, W.; Zheng, W.; Song, H.; Yu, W. W.; et al. Spontaneous Silver Doping and Surface Passivation of CsPbI3 Perovskite Active Layer Enable Light-Emitting Devices with an External Quantum Efficiency of 11.2%. ACS Energy Lett 2018, 1571-1577. (11) Yan, F.; Xing, J.; Xing, G.; Quan, L.; Tan, S. T.; Zhao, J.; Su, R.; Zhang, L.; Chen, S.; Zhao, Y.; et al. Highly Efficient Visible Colloidal Lead-Halide Perovskite Nanocrystal Light-Emitting Diodes. Nano Lett 2018, 18, (5), 3157-3164. (12) Zhao, X. G.; Yang, D.; Sun, Y.; Li, T.; Zhang, L.; Yu, L.; Zunger, A. Cu-In Halide Perovskite Solar Absorbers. J. Am. Chem. Soc 2017, 139, (19), 6718-6725. 17



Page 18 of 23

(13) Creutz, S. E.; Crites, E. N.; De Siena, M. C.; Gamelin, D. R. Colloidal Nanocrystals of Lead-Free Double-Perovskite (Elpasolite) Semiconductors: Synthesis and Anion Exchange To Access New Materials. Nano Lett 2018, 18, (2), 1118-1123. (14) Jellicoe, T. C.; Richter, J. M.; Glass, H. F.; Tabachnyk, M.; Brady, R.; Dutton, S. E.; Rao, A.; Friend, R. H.; Credgington, D.; Greenham, N. C.; et al. Synthesis and Optical Properties of Lead-Free Cesium Tin Halide Perovskite Nanocrystals. J. Am. Chem. Soc 2016, 138, (9), 2941-2944. (15) Zhou, C.; Tian, Y.; Wang, M.; Rose, A.; Besara, T.; Doyle, N. K.; Yuan, Z.; Wang, J. C.; Clark, R.; Hu, Y.; et al. Low-Dimensional Organic Tin Bromide Perovskites and Their Photoinduced Structural Transformation. Angew. Chem., Int. Ed. Engl 2017, 56, (31), 9018-9022. (16) Zhou, C.; Tian, Y.; Yuan, Z.; Lin, H.; Chen, B.; Clark, R.; Dilbeck, T.; Zhou, Y.; Hurley, J.; Neu, J.; et al. Highly Efficient Broadband Yellow Phosphor Based on Zero-Dimensional Tin Mixed-Halide Perovskite. ACS Appl. Mater. Interfaces 2017, 9, (51), 44579-44583. (17) Zhou, C.; Worku, M.; Neu, J.; Lin, H.; Tian, Y.; Lee, S.; Zhou, Y.; Han, D.; Chen, S.; Hao, A.; et al. Facile Preparation of Light Emitting Organic Metal Halide Crystals with Near-Unity Quantum Efficiency. Chem. Mater 2018, 30, (7), 2374-2378. (18) Leng, M.; Yang, Y.; Zeng, K.; Chen, Z.; Tan, Z.; Li, S.; Li, J.; Xu, B.; Li, D.; Hautzinger, M. P.; et al. All-Inorganic Bismuth-Based Perovskite Quantum Dots with Bright Blue Photoluminescence and Excellent Stability. Adv. Funct. Mater 2018, 28, (1), 1704446. 18


Page 19 of 23 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 Energy Letters

(19) Zhang, J.; Yang, Y.; Deng, H.; Farooq, U.; Yang, X.; Khan, J.; Tang, J.; Song, H. High Quantum Yield Blue Emission from Lead-Free Inorganic Antimony Halide Perovskite Colloidal Quantum Dots. ACS Nano 2017, 11, (9), 9294-9302. (20) Zhou, C.; Lin, H.; Tian, Y.; Yuan, Z.; Clark, R.; Chen, B.; van de Burgt, L. J.; Wang, J. C.; Zhou, Y.; Hanson, K.; et al. Luminescent Zero-Dimensional Organic Metal Halide Hybrids with Near-Unity Quantum Efficiency. Chem. Sci 2018, 9, (3), 586-593. (21) Lin, H.; Zhou, C.; Tian, Y.; Siegrist, T.; Ma, B. Low-Dimensional Organometal Halide Perovskites. ACS Energy Lett 2017, 3, (1), 54-62. (22) Lanzetta, L.; Marin-Beloqui, J. M.; Sanchez-Molina, I.; Ding, D.; Haque, S. A. Two-Dimensional Organic Tin Halide Perovskites with Tunable Visible Emission and Their Use in Light-Emitting Devices. ACS Energy Lett 2017, 2, (7), 1662-1668. (23) Weidman, M. C.; Seitz, M.; Stranks, S. D.; Tisdale, W. A. Highly Tunable Colloidal Perovskite Nanoplatelets through Variable Cation, Metal, and Halide Composition. ACS Nano 2016, 10, (8), 7830-7839. (24) Cao, D. H.; Stoumpos, C. C.; Farha, O. K.; Hupp, J. T.; Kanatzidis, M. G. 2D Homologous Perovskites as Light-Absorbing Materials for Solar Cell Applications. J. Am. Chem. Soc 2015, 137, (24), 7843-7850. (25) Stoumpos, C. C.; Cao, D. H.; Clark, D. J.; Young, J.; Rondinelli, J. M.; Jang, J. I.; Hupp, J. T.; Kanatzidis, M. G. Ruddlesden–Popper Hybrid Lead Iodide Perovskite 2D Homologous Semiconductors. Chem. Mater. 2016, 28, (8), 2852-2867. (26) Mao, L.; Tsai, H.; Nie, W.; Ma, L.; Im, J.; Stoumpos, C. C.; Malliakas, C. D.; Hao, F.; Wasielewski, M. R.; Mohite, A. D.; et al. Role of Organic Counterion in Lead- and 19



Page 20 of 23

Tin-Based Two-Dimensional Semiconducting Iodide Perovskites and Application in Planar Solar Cells. Chem. Mater. 2016, 28, (21), 7781-7792. (27) Xu, W.; Wang, T. Synergetic Effect of Blended Alkylamines for Copper Complex Ink To Form Conductive Copper Films. Langmuir 2017, 33, (1), 82-90. (28) Shukla, N.; Liu, C.; Jones, P. M.; Weller, D. FTIR Study of Surfactant Bonding to FePt Nanoparticles. J. Magn. Magn. Mater 2003, 266, (1), 178-184. (29) Mourdikoudis, S.; Liz-Marzán, L. M. Oleylamine in Nanoparticle Synthesis. Chem. Mater 2013, 25, (9), 1465-1476. (30) Dang, Y.; Zhou, Y.; Liu, X.; Ju, D.; Xia, S.; Xia, H.; Tao, X. Formation of Hybrid Perovskite Tin Iodide Single Crystals by Top-Seeded Solution Growth. Angew. Chem 2016, 128, (10), 3508-3511. (31) Cheng, Z.; Lin, J. Layered Organic–Inorganic Hybrid Perovskites: Structure, Optical Properties, Film Peparation, Patterning and Templating Engineering. CrystEngComm 2010, 12, (10), 2646-2662. (32) Era, M.; Maeda, K.; Tsutsui, T. Self-Organization Approach to Oorganic/Inorganic Quantum-Well Based on Metal Halide-Based Layer Perovskite. Thin Solid Films 1998, 331, (1), 285-290. (33) Zhou, C.; Lin, H.; Shi, H.; Tian, Y.; Pak, C.; Shatruk, M.; Zhou, Y.; Djurovich, P.; Du, M. H.; Ma, B. A Zero-Dimensional Organic Seesaw-Shaped Tin Bromide with Highly Efficient Strongly Stokes-Shifted Deep-Red Emission. Angew Chem Int Ed Engl 2018, 57, (4), 1021-1024. (34) Yamasaki, Y.; Ohno, N. Self-Trapped Excitons in Orthorhombic SnBr2. Int. J. Mod. 20


Page 21 of 23 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 Energy Letters

Phys. B 2001, 15, (28n30), 4009-4012. (35) Smith, M. D.; Karunadasa, H. I. White-Light Emission from Layered Halide Perovskites. Acc. Chem. Res 2018, 51, (3), 619-627. (36) Han, D.; Shi, H.; Ming, W.; Zhou, C.; Ma, B.; Saparov, B.; Ma, Y.-Z.; Chen, S.; Du, M.-H. Unraveling Luminescence Mechanisms in Zero-Dimensional Halide Perovskites. J. Mater. Chem. C 2018, 6, (24), 6398-6405. (37) Baldo, M. A.; O'Brien, D. F.; You, Y.; Shoustikov, A.; Sibley, S.; Thompson, M. E.; Forrest,

S.

R.

Highly

Efficient

Phosphorescent

Emission

from

Organic

Electroluminescent Devices. Nature 1998, 395, 151-154. (38) Lin, H.; Zhou, C.; Tian, Y.; Besara, T.; Neu, J.; Siegrist, T.; Zhou, Y.; Bullock, J.; Schanze, K. S.; Ming, W.; et al. Bulk Assembly of Organic Metal Halide Nanotubes. Chem Sci 2017, 8, (12), 8400-8404. (39) Yuan, Z.; Zhou, C.; Tian, Y.; Shu, Y.; Messier, J.; Wang, J. C.; van de Burgt, L. J.; Kountouriotis, K.; Xin, Y.; Holt, E.; et al. One-Dimensional Organic Lead Halide Perovskites with Efficient Bluish White-Light Emission. Nat. Commun. 2017, 8, 14051. (40) Yuan, Z.; Shu, Y.; Tian, Y.; Xin, Y.; Ma, B. A Facile One-Pot Synthesis of Deep Blue Luminescent Lead Bromide Perovskite Microdisks. Chem. Commun. 2015, 51, (91), 16385-16388. (41) Cheng, P.; Wu, T.; Liu, J.; Deng, W. Q.; Han, K. Lead-Free, Two-Dimensional Mixed Germanium and Tin Perovskites. J. Phys. Chem. Lett. 2018, 9, (10), 2518-2522. (42) Yuan, Z.; Zhou, C.; Messier, J.; Tian, Y.; Shu, Y.; Wang, J.; Xin, Y.; Ma, B. A Microscale Perovskite as Single Component Broadband Phosphor for Downconversion 21



Page 22 of 23

White-Light-Emitting Devices. Adv. Opt. Mater. 2016, 4, (12), 2009-2015. (43) Liu, F.; Ding, C.; Zhang, Y.; Ripolles, T. S.; Kamisaka, T.; Toyoda, T.; Hayase, S.; Minemoto, T.; Yoshino, K.; Dai, S.; et al. Colloidal Synthesis of Air-Stable Alloyed CsSn1–xPbxI3 Perovskite Nanocrystals for Use in Solar Cells. J. Am. Chem. Soc. 2017, 139, (46), 16708-16719. (44) Zhang, X.; Sun, C.; Zhang, Y.; Wu, H.; Ji, C.; Chuai, Y.; Wang, P.; Wen, S.; Zhang, C.; Yu, W. W. Bright Perovskite Nanocrystal Films for Efficient Light-Emitting Devices. J. Phys. Chem. Lett. 2016, 7, (22), 4602-4610. (45) Zhang, X.; Zhang, Y.; Yan, L.; Ji, C.; Wu, H.; Wang, Y.; Wang, P.; Zhang, T.; Wang, Y.; Cui, T.; et al. High Photocurrent PbSe Solar Cells with Thin Active Layers. J. Mater. Chem. A. 2015, 3, (16), 8501-8507. (46) Wang, J.; Wang, N.; Jin, Y.; Si, J.; Tan, Z.; Du, H.; Cheng, L.; Dai, X.; Bai, S.; He, H.; et al. Interfacial Control Toward Efficient and Low-Voltage Perovskite Light-Emitting Diodes. Adv. Mater 2015, 27, (14), 2311-2316. (47) Zhou, X.; He, J.; Liao, L. S.; Lu, M.; Ding, X. M.; Hou, X. Y.; Zhang, X. M.; He, X. Q.; Lee, S. T. Real-Time Observation of Temperature Rise and Thermal Breakdown Processes in Organic LEDs Using an IR Imaging and Analysis System. Adv. Mater. 2000, 12, (4), 265-269. (48) Tessler, N.; Harrison, N. T.; Thomas, D. S.; Friend, R. H. Current Heating in Polymer Light Emitting Diodes. Appl. Phys. Lett. 1998, 73, (6), 732-734. (49) Tessler, N. Lasers Based on Semiconducting Organic Materials. Adv. Mater. 1999, 11, (5), 363-370. 22


Page 23 of 23

ACS Energy Letters

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


Bright Orange Electroluminescence from Lead-Free Two-Dimensional

Recommend Documents