Recent Progress in Single-Crystalline Perovskite Research Including Crystal Preparation, Property Evaluation, and Applications

Abstract

Organic-inorganic lead halide perovskites are promising optoelectronic materials resulting from their significant light absorption properties and unique long carrier dynamics, such as a long carrier lifetime, carrier diffusion length, and high carrier mobility. These advantageous properties have allowed for the utilization of lead halide perovskite materials in solar cells, LEDs, photodetectors, lasers, etc. To further explore their potential, intrinsic properties should be thoroughly investigated. Single crystals with few defects are the best candidates to disclose a variety of interesting and important properties of these materials, ultimately, showing the increased importance of single-crystalline perovskite research. In this review, recent progress on the crystallization, investigation, and primary device applications of single-crystalline perovskites are summarized and analyzed. Further improvements in device design and preparation are also discussed.

Keywords: crystal growth; optoelectronic applications; perovskite; single crystal.

Figure 1

The crystal structures of perovskite materials with different symmetries: a) cubic phase, b) tetragonal phase, and c) orthorhombic phase.

Figure 2

Methods used for single‐crystal preparation and the basic theories behind these methods: a–c) low temperature‐induced single‐crystal growth during which the solubility of the perovskite will decrease with a lower solution temperature; d–f) schematic illustration of TSSG method and the single crystal obtained by this method; g–i) AVC method to prepare single‐crystalline perovskites and their shape and size recorded by a camera; j) the solubility curve of CH₃NH₃PbI₃ in GBL, which decreased with temperature at temperatures over 60 °C; k) the single‐crystalline perovskites obtained quickly with an ITC) method, which is based on the solubility curve in (j); l) a large single‐crystalline perovskite was prepared by repeating the ITC process several times. a–c) Reproduced with permission.61 Copyright 2015, RSC. d–f) Reproduced with permission.11 Copyright 2015, AAAS. g–i) Reproduced with permission.27 Copyright 2015, AAAS. j) Reproduced with permission.57 Copyright 2015, RSC. k) Reproduced with permission.28 Copyright 2015, published under the terms of CC‐BY 4.0 license. l) Reproduced with permission.55

Figure 3

The strategies used to modulate the shape and thickness of single‐crystalline perovskites and the corresponding crystals obtained by these methods: a) sphere‐shaped and stair‐shaped perovskite prepared using a round‐bottom test tube and a 2 mm curette; b) schematic illustration of the method to control and adjust the thickness of the perovskite wafers; c) pictures of the perovskite wafers with thicknesses from 150 µm to ≈mm;109 and d) a CTAC strategy to prepare a single‐crystalline film at the µm scale. a) Reproduced with permission.28 Copyright 2015, published under the terms of CC‐BY 4.0 license. b,c) Reproduced with permission.109 d) Reproduced with permission.56

Figure 4

Methods used to investigate the carrier transport and dynamic parameters and corresponding results: a,b) trap density, carrier mobility, and carrier concentration of the crystal disclosed using the SCLC method; c,d) TOF method and corresponding results revealing the carrier mobility of a single‐crystalline perovskite; carrier lifetime of perovskites disclosed by different ways: e,f) photoluminescence decay; g,h) transient absorption; and i,j) impedance and transient photovoltage decay methods. a,b,g,h) Reproduced with permission.28 Copyright 2015, Nature Publishing Group. c–f) Reproduced with permission.27 Copyright 2015, AAAS. i,j) Reproduced with permission.21 Copyright 2015, AAAS.

Figure 5

Light absorption and photoemission properties of single‐crystalline perovskites. Reproduced with permission.55

Figure 6

Single‐crystalline perovskite‐based solar cell devices with different configurations: a) thick single‐crystalline perovskite solar cell with a semitransparent Au electrode as the HTL and Ga electrode as the electron transport layer. Reproduced with permission.21 Copyright 2015, AAAS. b) J–V curve of the solar cell shown in figure (a); c) the device structure of a single‐crystalline MAPbBr₃ film‐based solar cell and its photovoltaic performance. Reproduced with permission.56 d) Effect of the single‐crystalline MAPbBr₃ thickness on the photovoltaic performance of single‐crystalline solar cells; e) schematic illustration of a lateral structured single‐crystalline perovskite solar cell and its photovoltaic performance f). Reproduced with permission.128

Figure 7

The single‐crystalline perovskite‐based photodetectors and their performances: a) a photoconductive photodetector with a single‐crystalline perovskite as the working media and b) its corresponding responsivity and c) response speed. Reproduced with permission.81 Copyright 2015, published under the terms of CC‐BY 4.0 license. d,g) a photovoltaic photodetector with an asymmetrical electrode to collect photogenerated holes and electrons and their corresponding device performance e, f, h, i). d–f) Reproduced with permission.129 Copyright 2016, RSC. g–i) Reproduced with permission.106 Copyright 2016, Nature Publishing Group.

Figure 8

Laser emission from perovskites with special shapes: hexagonal plate, microdisk, and nanowire; a) the working mechanism of a WGM type cavity produced by perovskite crystals and its laser emission properties (b, c). Reproduced with permission.132 Copyright 2014, ACS. d) Microdisk‐based WGM cavity achieving laser emission and its threshold properties (e, f); g) nanowire‐coupled microdisk producing directional laser emission. Reproduced with permission.83 h) Schematic illustration of laser emission from a perovskite nanowire, which naturally forms a FP cavity to support laser emission and laser emission properties (i, j). Reproduced with permission.133 Copyright 2015, Nature Publishing Group.