高压下混合卤化物钙钛矿CsPb(I_(x)Br_(1-x))_(3)纳米晶在激光诱导下的相分离行为  

Laser-Induced Phase Separation of Mixed-Halide CsPb(I_(x)Br_(1-x))_(3) Perovskite Nanocrystals under High Pressure

作　　者：吴迪 李娜娜 刘炳炎 关嘉怡 李明涛 闫立敏 王碧涵 董洪亮 毛禺鈜 杨文革 WU Di;LI Nana;LIU Bingyan;GUAN Jiayi;LI Mingtao;YAN Limin;WANG Bihan;DONG Hongliang;MAO Yuhong;YANG Wenge(Center for High Pressure Science and Technology Advanced Research,Shanghai 201203,China;Department of Materials Science and Engineering,China University of Petroleum(East China),Qingdao 266580,Shandong,China;Department of Physics,Beijing Institute of Technology,Beijing 100081,China;State Key Laboratory of Superhard Materials,Department of Physics,Jilin University,Changchun 130012,Jilin,China)

机构地区：[1]北京高压科学研究中心,上海201203 [2]中国石油大学(华东)材料科学与工程学院,山东青岛266580 [3]北京理工大学物理学院,北京100081 [4]吉林大学物理学院,超硬材料国家重点实验室,吉林长春130012

出　　处：《高压物理学报》2024年第5期96-103,共8页Chinese Journal of High Pressure Physics

基　　金：国家自然科学基金(U1930401)。

摘　　要：混合卤化物类钙钛矿具有多种优异的光电特性,如随卤素成分变化而大范围可调的带隙、高荧光量子产率等,是制备太阳能电池和发光二极管等光电材料的理想候选材料。然而,混合卤化物钙钛矿的稳定性较差,如在强光照条件下会发生相分离,这种不稳定性阻碍了它们在光电领域的广泛应用,因此,研究其相分离的内在机理和控制方法对于改善其特性以实现实际应用至关重要。针对强激光照射下具有不同组分的CsPb(I_(x)Br_(1-x))_(3)纳米晶,系统研究了其激光诱导相分离随压强的变化,发现不同I/Br比例的CsPb(I_(x)Br_(1-x))_(3)纳米晶具有不同的激光诱导相分离特征:x<0.1的富溴样品随着激光照射而迅速产生CsPbBr3纯相,并实现较大的荧光量子产率增益;0.10.9低溴含量样品则只产生荧光峰宽化,并伴随荧光强度的快速降低。将CsPb(I_(x)Br_(1-x))_(3)纳米晶置于准静水压强环境中,观察到富溴样品和较多溴含量样品中的相分离随着压强的升高而迅速减缓,并在约0.1 GPa的较低压强下被极大程度地抑制,而低溴含量样品的相分离则随压强上升而增强。这些发现为理解和克服相关光电材料在强光工作环境中的应用问题提供了一种有效的解决途径。Mixed-halide perovskites have a variety of excellent photovoltaic properties,including the band gap that is widely tunable with the halogen composition,high photoluminescence quantum yield(PLQY),and so on,making them ideal candidates for the photovoltaic device applications such as solar cells and light-emitting diodes.However,mixed-halide perovskites often encounter phase separation under light illumination,which hinders their wide application in optoelectronics.Therefore,investigating the intrinsic mechanism and controlling methods of their phase separation is crucial to improve their properties for practical applications.In this work,a systematic study of the laser-induced phase separation of CsPb(I_(x)Br_(1-x))_(3) nanocrystals with different compositions under strong laser irradiation at different pressures was carried out.We discovered that CsPb(I_(x)Br_(1-x))_(3) nanocrystals with different I/Br ratios possess different characteristics of laser-induced phase separation,for example,at ambient pressure,the bromine-rich samples with x<0.1 produce nearly full-bromide CsPbBr3 phase rapidly and achieve a large PLQY gain;the samples with 0.1<x<0.9 clearly form a new photoluminescence(PL)peak at lower wavelength,which represents the bromine-rich phase generation;while the samples with low bromine content with x>0.9 only produce a broadening of the PL peak as well as a rapid decrease of the PL intensity.By subjecting CsPb(I_(x)Br_(1-x))_(3) nanocrystals to a quasi-hydrostatic pressure environment,it was observed that phase separation in brominerich samples(x<0.9)rapidly slowed down with increasing pressure and was largely suppressed at a mild pressure of about 0.1 GPa,while phase separation in samples with low bromine content was enhanced with increasing pressure.These findings provide an effective and practical way to understand and overcome the problem of application of relevant photoelectric devices in intense light environments.

关 键 词：压强调控 激光诱导 CsPb(I_(x)Br_(1-x))_(3)相分离 原位表征 

分 类 号：O521.2[理学—高压高温物理]