Large-Scale Thin CsPbBr3 Single-Crystal Film Grown on Sapphire via Chemical Vapor Deposition: Toward Laser Array Application
Large-Scale Thin CsPbBr3 Single-Crystal Film Grown on Sapphire via Chemical Vapor Deposition: Toward Laser Array Application
复制标题
通过化学气相沉积在蓝宝石上生长大尺寸 CsPbBr3 单晶薄膜：面向激光阵列应用
DOI：
10.1021/acsnano.0c06380
复制
发表时间：
2020
期刊：
影响因子：
17.1
通讯作者：
Liu Xinfeng
中科院分区：
文献类型：
--
作者：
Zhong Yangguang;Liao Kun;Du Wenna;Zhu Jiangrui;Shang Qiuyu;Zhou Fan;Wu Xianxin;Sui Xinyu;Shi Jianwei;Yue Shuai;Wang Qi;Zhang Yanfeng;Zhang Qing;Hu Xiaoyong;Liu Xinfeng
钙钛矿单晶具有优良的电物理性能，是制备激光器、发光二极管、光电探测器等光电器件的理想材料。然而，通过气相外延生长具有高光学增益的大尺寸钙钛矿单晶薄膜（SCF）仍然具有挑战性。本文介绍了一种在蓝宝石衬底上制备大尺寸超薄CsPbBr 3SCFs（~ 300 nm）的简单方法。高温是控制低反应物浓度和足够的表面扩散长度以生长连续CsPbBr 3SCF的关键参数。通过对载流子动力学的综合研究，阐明了在低载流子密度下，与陷阱相关的激子复合起主要作用，而随着载流子密度的增加，激子和自由载流子的复合共存，直到自由载流子起主导作用。在室温下，当泵浦功率为阈值的20倍时，获得了高达1255 cm-1的放大自发辐射，阈值为1.8 μJ cm-2。采用聚焦离子束刻蚀方法制备了微阵列盘，并在直径为3 μm的微阵列盘上获得了单模激光输出，阈值为1.6 μJ cm-2。实验结果不仅为大规模制备CsPbBr 3超导光纤提供了一种可行的方法，而且为提高CsPbBr 3的光电应用提供了一个竞技场。
Single-crystal perovskites with excellent photophysical properties are considered to be ideal materials for optoelectronic devices, such as lasers, light-emitting diodes and photodetectors. However, the growth of large-scale perovskite single-crystal films (SCFs) with high optical gain by vapor-phase epitaxy remains challenging. Herein, we demonstrated a facile method to fabricate large-scale thin CsPbBr3SCFs (∼300 nm) on thec-plane sapphire substrate. High temperature is found to be the key parameter to control low reactant concentration and sufficient surface diffusion length for the growth of continuous CsPbBr3SCFs. Through the comprehensive study of the carrier dynamics, we clarify that the trapped-related exciton recombination has the main effect under low carrier density, while the recombination of excitons and free carriers coexist until free carriers plays the dominate role with increasing carrier density. Furthermore, an extremely low-threshold (∼8 μJ cm–2) amplified spontaneous emission was achieved at room temperature due to the high optical gain up to 1255 cm–1at a pump power of 20 times threshold (∼20Pth). A microdisk array was prepared using a focused ion beam etching method, and a single-mode laser was achieved on a 3 μm diameter disk with the threshold of 1.6 μJ cm–2. Our experimental results not only present a versatile method to fabricate large-scale SCFs of CsPbBr3but also supply an arena to boost the optoelectronic applications of CsPbBr3with high performance.