A位取代和缺陷钝化实现钙钛矿薄膜的低阈值红光放大自发辐射  

Red Low-threshold Amplified Spontaneous Emission of Perovskite Films Achieved by A-site Substitution and Defect Passivation

作　　者：王亮[1] 严梦彤 李妍 吕梅 陆红波 朱俊 WANG Liang;YAN Mengtong;LI Yan;LYU Mei;LU Hongbo;ZHU Jun(Anhui Provincial Engineering Research Center of Semiconductor Inspection Technology and Instrument,Anhui Province Key Laboratory of Measuring Theory and Precision Instrument,School of Instrument Science and Opto-electronics Engineering,Hefei University of Technology,Hefei 230009,China;School of Chemistry and Chemical Engineering,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学仪器科学与光电工程学院,安徽省半导体检测技术与仪器工程研究中心,测量理论与精密仪器安徽省重点实验室,安徽合肥230009 [2]合肥工业大学化学与化工学院,安徽合肥230009

出　　处：《发光学报》2024年第7期1068-1076,共9页Chinese Journal of Luminescence

基　　金：国家自然科学基金(52302237)。

摘　　要：作为发红光的光学增益介质,CsPbI_(2)Br钙钛矿材料具有良好的热稳定性和合适的光学带隙,引起了研究者的广泛关注。然而,溶液法制备的CsPbI2Br薄膜在高湿度环境下易发生相变,同时薄膜存在大量缺陷,阻碍了其性能提升。鉴于此,采用部分FA^(+)(CH_(4)N_(2)^(+))进行A位取代以提高钙钛矿薄膜的相稳定性,然后利用聚甲基丙烯酸甲酯(PMMA)对钙钛矿薄膜进行表面钝化。得益于FA^(+)阳离子带来的薄膜形貌的改善和PMMA良好缺陷钝化效果,实现了Cs_(0.7)FA_(0.3)PbI_(2)Br钙钛矿薄膜的低阈值红光放大自发辐射(ASE),其发射波长为689 nm,纳秒激光激发下的阈值为15μJ/cm^(2)。同时,该薄膜具有良好的疏水性和光稳定性,在大气湿度环境下(RH为(40±10)%),采用3000μJ/cm^(2)脉冲激光持续照射120 min,其ASE强度仍能维持其初始值的93%。这项工作为实现低阈值高稳定的红光ASE和激光提供了参考。Lead halide perovskite has shown great potential as a new generation of optoelectronic materials due to its adjustable optical band gap,high luminous color purity,high carrier mobility,and solution-processibility.Cur⁃rently,amplified spontaneous emission(ASE)and laser have been realized in the blue,green,red,and even infra⁃red ranges for perovskite material.As a red light-emitting optical gain medium,CsPbI_(2)Br perovskite material has good thermal stability and a suitable optical band gap and has attracted extensive attention from researchers.Howev⁃er,CsPbI_(2)Br films prepared by the solution method are prone to phase transition in high-humidity environments,and there are many defects in the films,which hinder their further development.To improve the phase stability of CsPbI_(2)Br perovskite films,the A-site is partially substituted by FA^(+)(CH_(4)N_(2)^(+))in this work.The tolerance factor of the perovskite structure is increased after FA^(+)substitution,which can effectively improve the phase stability of the perovskite films.Meanwhile,the morphology and crystallinity of the perovskite films are improved.To reduce the non-radiative recombination caused by the surface defects,polymethyl methacrylate(PMMA)is used to passivate the surface of the perovskite films.The C==O bond in PMMA can effectively bind to the undercoordinated Pb^(2+)on the surface of perovskite,resulting in a good defect passivation effect and effective inhibition of non-radiative recombina⁃tion.Thanks to the improvement of the film morphology caused by FA^(+)cation and the PMMA passivation,a low-thresh⁃old,15μJ/cm^(2) under nanosecond laser excitation is achieved for the red ASE of the Cs0.7FA0.3PbI_(2)Br perovskite film.At the same time,the film has good hydrophobicity and photostability.Under the air humidity environment(RH(40±10)%),the ASE intensity remains at 93%of its initial value after a pulsed laser irradiation of 3000μJ/cm^(2) for 120 min.This work provides a reference for realizing low-threshold and high-stability red

关 键 词：钙钛矿 放大自发辐射 阳离子取代 缺陷钝化 

分 类 号：O482.31[理学—固体物理]