二维范德瓦耳斯异质结Cs_(3)X_(2)I_(9)/InSe(X=Bi,Sb)的光电性能  

Photovoltaic properties of two-dimensional van der Waals heterostructure Cs_(3)X_(2)I_(9)/InSe(X=Bi,Sb)

作　　者：熊祥杰 钟防 张资文 陈芳[1] 罗婧澜 赵宇清 朱慧平 蒋绍龙 Xiong Xiang-Jie;Zhong Fang;Zhang Zi-Wen;Chen Fang;Luo Jing-Lan;Zhao Yu-Qing;Zhu Hui-Ping;Jiang Shao-Long(Hunan Provincial Key Laboratory of Intelligent Sensors and New Sensor Materials,School of Physics and Electronics Science,Hunan University of Science and Technology,Xiangtan 411201,China;Adam Smith School,University of Glasgow,Glasgow G128QQ,UK;Key Laboratory of Science and Technology on Silicon Devices,Institute of Microelectronics,Chinese Academy of Sciences,Beijing 100029,China;Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area(Guangdong),Shenzhen 518045,China)

机构地区：[1]湖南科技大学物理与电子科学学院,智能传感器与新型传感器材料湖南省重点实验室,湘潭411201 [2]格拉斯哥大学亚当史密斯学院,格拉斯哥G128QQ [3]中国科学院微电子研究所,硅器件技术重点实验室,北京100029 [4]粤港澳大湾区(广东)量子科学中心,深圳518045

出　　处：《物理学报》2024年第13期229-237,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12204166);湖南省自然科学基金(批准号:2024JJ5132);国家重点研发项目(批准号:2023YFB3611700);湖南科技大学科研启动基金(批准号:E51996)资助的课题。

摘　　要：设计二维半导体范德瓦耳斯异质结是一种实现多功能微电子器件的有效策略.本文构筑了二维钙钛矿Cs_(3)X_(2)I_(9)(X=Bi,Sb)和铟锡InSe的范德瓦耳斯异质结Cs_(3)X_(2)I_(9)/InSe.基于密度泛函理论的第一性原理方法,计算了其几何、电子结构、光学性质.研究表明,二维Cs3Bi2I9/InSe和Cs3Sb2I9/InSe异质结为II型能带排列,且带隙分别为1.61 eV和1.19 eV,可见光和紫外光范围内具有较高的吸收系数.基于形变势理论和类氢原子模型的计算,二维Cs_(3)X_(2)I_(9)/InSe异质结显示了较高的电子迁移速率和激子结合能.基于Ⅱ型排列的能带结构和肖克利-奎伊瑟极限(Shockley-Queisser limit),对比研究了光电转换效率.此外,进一步探究了双轴应变对二维异质结Cs_(3)X_(2)I_(9)/InSe光电特性的调控及其规律.上述研究为未来设计高效的二维范德瓦耳斯光电子器件提供了理论依据.Two-dimensional semiconductor heterostructures have excellent physical properties such as high light absorption coefficients,large diffusion lengths,high carrier mobility rates,and tunable energy band structures,which have great potential in the field of optoelectronic devices.Therefore,designing two-dimensional(2D)semiconductor van der Waals heterostructures is an effective strategy for realizing multifunctional microelectronic devices.In this work,the 2D van der Waals heterostructure Cs_(3)X_(2)I_(9)/InSe of non-lead Perovskite Cs_(3)X_(2)I_(9)and indium-tin InSe is constructed to avoid the toxicity and stability problems of lead-based Perovskites.The geometry,electronic structure,and optical properties are calculated based on the firstprinciples approach of dens it y-functional theory.It is shown that the 2D Cs_3Bi_2I_9/InSe and Cs_3Sb_2I_9/InSe heterostructures are of type-II energy band arrangement and have band gaps of 1.61 eV and 1.19 eV,respectively,with high absorption coefficients in the visible range and UV range reaching to 5×10~5 cm~(-1).The calculation results from the deformation potential theory and the hydrogen-like atom model show that the 2D Cs_(3)X_(2)I_(9)/InSe heterostructure has a high exciton binding energy(~0.7 eV)and electron mobility rate(~700 cm~2/(V·s)).The higher light absorption coefficient,carrier mobility,and exciton energy make the 2D Cs_(3)X_(2)I_(9)/InSe heterostructures suitable for photo luminescent devices.However,the energy band structure based on the Shockley-Queisser limit and type-Ⅱarrangement shows that the intrinsic photoelectric conversion efficiency(PCE)of the 2D Cs_(3)X_(2)I_(9)/InSe heterostructure is only about 1.4%,which is not suitable for photovoltaic solar energy.In addition,the modulation and its effect of biaxial strain on the photovoltaic properties of 2D Cs_(3)X_(2)I_(9)/InSe heterostructures are further investigated.The results show that biaxial strain can improve the visible absorption coefficient of 2D Cs_(3)X_(2)I_(9)/InSe heterostructure,but canno

关 键 词：二维异质结 光电转换效率 第一性原理计算 应变工程 

分 类 号：O469[理学—凝聚态物理]