Toward Long-Term Stability: Single-Crystal Alloys of Cesium-Containing Mixed Cation and Mixed Halide Perovskite

Abstract

Perovskite solar cells are strong competitors for silicon-based ones, but suffer from poor long-term stability, for which the intrinsic stability of perovskite materials is of primary concern. Herein, we prepared a series of well-defined cesium-containing mixed cation and mixed halide perovskite single-crystal alloys, which enabled systematic investigations on their structural stabilities against light, heat, water, and oxygen. Two potential phase separation processes are evidenced for the alloys as the cesium content increases to 10% and/or bromide to 15%. Eventually, a highly stable new composition, (FAPbI3)0.9(MAPbBr3)0.05­(CsPbBr3)0.05, emerges with a carrier lifetime of 16 μs. It remains stable during at least 10 000 h water–oxygen and 1000 h light stability tests, which is very promising for long-term stable devices with high efficiency. The mechanism for the enhanced stability is elucidated through detailed single-crystal structure analysis. Our work provides a single-crystal-based paradigm for stability investigation, leading to the discovery of stable new perovskite materials.

Unveiling the Photo‐ and Thermal‐Stability of Cesium Lead Halide Perovskite Nanocrystals

“…[12,[19][20] Most reported syntheses of CsPbX 3 follow the work of Protesescu et al who demonstrated a simple, solution-based synthesis for nanocrystals with high luminescence. [26,40] The photophysics of MAPbX 3 nanocrystals have been extensively studied, [41][42][43][44][45][46][47][48][49][50] and there are several reports on various luminescence properties of CsPbX 3 . [19,22,[36][37][38][39] In addition, triple-cation (Cs,formamidinium,methylammonium)PbX 3 materials have been developed with the goal of increasing stability while maintaining bright luminescence.…”

“…[19,22,[36][37][38][39] In addition, triple-cation (Cs,formamidinium,methylammonium)PbX 3 materials have been developed with the goal of increasing stability while maintaining bright luminescence. [26,40] The photophysics of MAPbX 3 nanocrystals have been extensively studied, [41][42][43][44][45][46][47][48][49][50] and there are several reports on various luminescence properties of CsPbX 3 . [51][52][53][54] Park et al observed strong photon antibunching as well as blinking behavior ascribed to charge/discharge events triggered by photoionization in CsPbBr 3 and CsPbI 3 .…”

Polymer/Inorganic Hole Transport Layer for Low-Temperature-Processed Perovskite Solar Cells

“…The halide perovskite used for photovoltaics has a typical AMX 3 crystal structure, where A is a monovalent cation, such as Cs + , Rb + , CH 3 NH 3 + , NH 2 CH = NH 2 + , CH 3 CH 2 NH 3 + ; M = Pb 2 + , Sn 2 + ; and X is a halide, such as Cl -, Bror I - [3]. At the same time, employing a mixed-cation and mixed-halide perovskite composition can dramatically improve the performance and stability of PSCs [4,5]. In a typical PSC, the perovskite layer is deposited between a metal oxide electron transport layer (ETL), with either a mesoporous or planar structure, and a hole-transport layer (HTL).…”

Effects of methylamine doping on the stability of triple cation (FA0.95−xMAxCs0.05)PbI3 single crystal perovskites

“…15 The high light absorption 16 and tunable cation components [17][18][19] of perovskites make them promising for application in PSCs. However, compared with commercial silicon-based solar cells (with more than 20 years of service life), 20 the undesirable stability of PSCs still hinders their rapid development and widespread use. The performance of perovskite photovoltaic devices was threatened by light, heat and water-oxygen, [21][22][23][24][25] and the main reason is the instability of the perovskite material itself.…”