Band structure engineering of two-dimensional semiconductors

Abstract

As a fundamental property of semiconductors, the band structure is crucial in the study and application of semiconductors. As a consequence, various band engineering methods are proposed to tune the band structure of semiconductors. Here, we study the band structure engineering in two different two-dimensional (2D) semiconductors: transition metal dichalcogenides (TMDCs) heterobilayers and hybrid layered double perovskites (HLDPs). The first part is about TMDCs HBLs. We find that The interlayer distance between MoSe₂ and WSe₂ layers changes from 6.6 Å to 7.7 Å with two different opposite orders, which greatly affects the band structures of the HBL system. The second part is about HLDPs. We study the band structures of PEA₄AgFeCl₈ and PEA₄NaFeCl₈. Our calculations suggest that the different contributions of Na and Ag elements to valence band maximum leads to different band gaps of PEA₄AgFeCl₈ and PEA₄NaFeCl₈.

Date of Award	2023
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology
Supervisor	Junwei LIU (Supervisor)