Van der Waals epitaxy of type-Ⅱ band alignment CsPbI_(3)/TMDC heterostructure for optoelectronic applications  

作　　者：Chang Lu Shunhui Zhang Meili Chen Haitao Chen Mengjian Zhu Zhengwei Zhang Jun He Lin Zhang Xiaoming Yuan 

机构地区：[1]Hunan Key Laboratory of Super Microstructure and Ultrafast Process,School of Physics,Central South University,Changsha 410083,China [2]College of Advanced Interdisciplinary Studies&Hunan Provincial Key Laboratory of Novel Nano-Optoelectronic Information Materials and Devices,National University of Defense Technology,Changsha 410073,China

出　　处：《Frontiers of physics》2024年第5期95-107,共13页物理学前沿（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.61974166 and 62274184);the Hunan Provincial Natural Science Foundation of China(Grant Nos.2021JJ20080 and 2021JJ20077)。

摘　　要：Van der Waals epitaxy allows heterostructure formation without considering the lattice match requirement,thus is a promising method to form 2D/2D and 2D/3D heterojunction.Considering the unique optical properties of CsPbI_(3) and transition metal dichalcogenides(TMDCs),their heterostructure present potential applications in both photonics and optoelectronics fields.Here,we demonstrate selective growth of cubic phase CsPbI_(3) nanofilm with thickness as thin as 4.0 nm and Zigzag/armchair orientated nanowires(NWs)on monolayer WSe_(2).Furthermore,we show growth of CsPbI_(3) on both transferred WSe_(2) on copper grid and WSe_(2) based optoelectrical devices,providing a platform for structure analysis and device performance modification.Transmission electron microscopy(TEM)results reveal the epitaxial nature of cubic CsPbI_(3) phase.The revealed growth fundamental of CsPbI_(3) is universal valid for other twodimensional substrates,offering a great advantage to fabricate CsPbI_(3) based van der Waals heterostructures(vdWHs).X-ray photoelectron spectroscopy(XPS)and optical characterization confirm the type-II band alignment,resulting in a fast charger transfer process and the occurrence of a broad emission peak with lower energy.The formation of WSe_(2)/CsPbI_(3) heterostructure largely enhance the photocurrent from 2.38 nA to 38.59 nA.These findings are vital for bottom-up epitaxy of inorganic semiconductor on atomic thin 2D substrates for optoelectronic applications.

关 键 词：van der Waals epitaxy band alignment growth fundamental charge transfer PHOTODETECTOR 

分 类 号：O43[机械工程—光学工程]