Effects of Components Modulation on the Type of Band Alignments for PbI2/WS2 van der Waals Heterostructure. Issue 7 (4th May 2020)

• Record Type: Journal Article
• Authors: Qian, Meng-Ya; Yu, Zhuo-Liang; Wan, Qiang; He, Peng-Bin; Liu, Biao; Yang, Jun-Liang; Xu, Chun-Mei; Cai, Meng-Qiu
• Is Part Of: Physica status solidi. Volume 14:Issue 7(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-05-04
• Subjects: band alignment -- components modulation -- density functional theory calculations -- semiconductor-based van der Waals heterostructures; Solid state physics -- Periodicals; 530.4105
• DOI: 10.1002/pssr.202000016
• Languages: English
• ISSNs: 1862-6254

Abstract

Abstract : Building semiconductor‐based van der Waals heterostructures (vdWHs) based on 2D materials can integrate the excellent properties of single materials to promote the development of an application for optoelectronics. In general, semiconductor‐based vdWHs have different types of band alignments related to the performance of equipment. However, it is greatly challenging to achieve controllable types of band alignment for a single heterojunction. Herein, the electronic and optical properties of the lead iodide/tungsten disulfide (PbI2 /WS2 ) heterostructure are investigated systematically by density functional theory (DFT) calculation. A Type‐I–Type‐II transition of band alignments in PbI2 /WS2 vdWHs is achieved by partly replacing the S atom in WS2 monolayer with Se atom. The reason lies in the change of band structure which can be attributed to a transformation in the conduction band minimum (CBM) from the W 5d and S 3p states to Pb 6p orbital in PbI2 /WS2 vdWHs. Moreover, the averaged hole carrier effective mass of the PbI2 /WSe2 vdWH has a minimum. The results may provide a direction to explore the transformation in band alignment in semiconductor‐based vdWHs for potential photoelectric applications. Abstract : The composition modulation‐induced transformation from Type‐I lead iodide/tungsten disulfide (PbI2 /WS2 ) van der Waals heterostructure (vdWH) to Type‐II is realized by substituting the sulphur (S) atom with selenium (Se). The results may provide a direction to explore the transformation in band alignment in semiconductor‐based vdWHs for potential photoelectric applications.