Hybrid organic–inorganic lead halide perovskites have been investigated extensively within the last decades, for its great potential in efficient solar cells and as an ideal light source. Among the studies on stimulated emission (SE), the emission is either out-of-plane for polycrystalline films or in-plane with randomly aligned single microcrystals and nanowires. In this work, we revealed in-plane propagation of SE from bromine-based perovskite polycrystalline thin films (CH₃NH₃PbBr₃, or MAPbBr₃). The output from in-plane SE is an order higher than the out-of-plane emission. It is proposed that large crystalline flakes in the films lead to the in-plane lasing phenomena. The output coupling can be found at grain boundaries, intergrain gaps, and artificial structures. Simulative results support the experimental phenomenon that large crystalline grains are profitable for in-plane propagation and over 90% photons can be sufficiently outcoupled when the gap is larger than a micron. Considering the fabrication and handling convenience, we propose that the MAPbBr₃ thin films can be easily integrated for in-plane applications as the light source for photonic chips etc.

中文翻译：

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多晶 CH3NH3PbBr3 钙钛矿薄膜的面内受激发射

在过去的几十年中，混合有机-无机卤化铅钙钛矿因其在高效太阳能电池中的巨大潜力和作为理想光源的巨大潜力而​​得到了广泛的研究。在受激发射 (SE) 的研究中，发射要么是多晶薄膜的平面外发射，要么是随机排列的单个微晶和纳米线的平面内发射。在这项工作中，我们揭示了 SE 从溴基钙钛矿多晶薄膜（CH ₃ NH ₃ PbBr ₃或 MAPbBr ₃）。面内 SE 的输出比面外发射高一个数量级。有人提出，薄膜中的大晶体薄片会导致面内激光现象。输出耦合可以在晶界、晶间间隙和人造结构处找到。模拟结果支持了大晶粒有利于面内传播的实验现象，当间隙大于一微米时，超过 90% 的光子可以充分外耦合。考虑到制造和处理的便利性，我们建议 MAPbBr ₃薄膜可以很容易地集成用于面内应用，作为光子芯片等的光源。