CsPbBr_(3)纳米晶电子辐照效应研究

Effect of electron irradiation on CsPbBr_(3)perovskite nanocrystal

钙钛矿材料具有优异的光学性能和较高的载流子迁移率,成为空间太阳能电池领域极具竞争力的材料。然而空间粒子辐照容易改变材料结构和光学性能,导致其性能下降。为了探究电子辐照对CsPbBr_(3)材料结构与光学特性的影响规律,本文开展了CsPbBr_(3)材料电子辐照实验,利用高分辨透射电子显微镜表征CsPbBr_(3)纳米晶微观形貌,并通过X射线衍射分析和X射线光电子能谱分析进一步探究晶体结构的变化趋势。研究发现:电子辐照后CsPbBr_(3)纳米晶形貌变得粗糙,尺寸明显减小,并且纳米晶在高剂量电子辐照下变得紧凑,形成纳米团簇。其次,通过稳态紫外-可见吸收光谱图与光致发光谱图表征CsPbBr_(3)材料的光学性能,并利用第一性原理计算分析辐照后晶格膨胀带来的带隙变化。研究证明电子辐照后纳米晶颜色加深,影响钙钛矿的透光率,进而增强了样品对光的吸收性能,同时电子辐照能够分解CsPbBr_(3)纳米晶,特别是高剂量辐照后其光致发光性能降低了53.7%~78.6%。本文研究结果为钙钛矿纳米晶空间辐射损伤机理及应用研究提供了数据支撑。

With excellent optical properties and high carrier mobility,perovskite materials have become highly competitive materials in the field of space solar cells.However,space particle irradiation can change the structure and optical properties of materials,leading to a rapid degradation of device performance.In order to investigate the influence of electron irradiation on the structure and optical properties of CsPbBr_(3)nanocrystals,we conducted electron irradiation experiments on CsPbBr_(3)materials,characterized the microscopic morphology of CsPbBr_(3)nanocrystals by high-resolution transmission electron microscopy.Moreover,we in-vestigated the variation trend of crystal structure by X-ray diffraction analysis and X-ray photoelectron spec-troscopy analysis.The results revealed electron irradiation caused the CsPbBr_(3)nanocrystals to become rough and significantly decrease in size.The nanocrystal became compact and formed nanocluster under high-dose electron irradiation.Furthermore,the optical properties of CsPbBr_(3)materials were characterized using steady-state UV-Vis absorption spectra and photoluminescence spectra.The analysis of lattice expansion-in-duced bandgap changes after irradiation was performed using first principles calculations.It is demonstrated that electron irradiation deepened the color of nanocrystals and affected the light transmittance of CsPbBr_(3)nanocrystalline,thereby enhancing the optical absorption performance of the samples.However,electron ir-radiation also led to the decomposition of CsPbBr_(3)nanocrystals,resulting in a significant reduction in lumin-escence intensity of the CsPbBr_(3)by 53.7%−78.6%after high-dose irradiation.These findings provide valu-able data support for the study of spatial radiation damage mechanisms and the application of perovskite nanocrystals.