Quasi‐CW Amplified Spontaneous Emission in Air‐Processed Quasi‐2D Perovskite Thin Films with High Stability

Abstract

Due to the hydrophobic organic cations, quasi‐two‐dimensional (quasi‐2D) lead halide perovskite materials have shown better moisture resistance. However, the inappropriate multiphase structure in the quasi‐2D perovskite films seriously affects the efficient transport of energy from low‐n domains to high‐n domains, especially when prepared in air. Herein, the study develops efficient quasi‐2D perovskite films in 30% ± 10% humidity and studies their amplified spontaneous emission (ASE) properties. It can be seen that the phase disproportionation of the quasi‐2D perovskite films prepared in air is greatly suppressed by manipulating the crystallization kinetics of the multiphase structure via using the organic additive benzimidazole (BI), thereby enabling a narrowed phase distribution. Due to the improvement in energy transfer efficiency, surface roughness, and humidity stability, the ASE with a low threshold of 13.4 µJ cm−2 is realized under the quasi‐continuous pumping condition, which is significantly <28.8 µJ cm−2 of the pristine film. Furthermore, the introduction of BI organic additive enhanced the number of peak intensity half‐decay pulses to as high as 5.6 × 107, indicating a good operating stability of the BI‐treated films. This work suggests that the BI‐treated quasi‐2D perovskite films provide the possibility for preparing high‐performance lasers in air.