Bandgap Tuned WS2 Thin‐Film Photodetector by Strain Gradient in van der Waals Effective Homojunctions
Abstract
Van der Waals (vdW) heterostructures (or heterojunctions) are formed by stacking two different 2D materials (e.g., graphene, h‐BN, or transition metal dichalcogenides) across vdW gaps. In a type‐II heterojunction, 2D semiconductors are aligned with staggered bandgaps, which can effectively separate electron and hole carriers, and enable promising high‐performance photovoltaics and photodetectors. Herein, an effective vdW‐homojunction is reported, formed by one 2D material (2H‐WS2) with vdW gap engineering leading to different electronic structures and type‐II junction formation. WS2 films are synthesized by W metal deposition and controlled sulfurization method leading to a nonuniform vdW gap strain in the film. The vdW strain gradients in multilayer WS2 films are confirmed by transmission electron microscopy analysis, and the modeling by density functional theory shows an effective type‐II homojunction formation via modulated bandgaps by the vdW gap strains. The superior performance of a broadband photodetector application is confirmed by photoluminescence and photocurrent experiments.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 20, 2021
- Source ID
- 10.1002/adom.202101310
Entities
People
- Bok Ki Min
- Choon-Gi Choi
- Dongwoo Suh
- Dongwook Kim
- Jeongwoon Hwang
- Kyeongjae Cho
- Seong Jun Kim
- Shuvra Mondal
- Van‐tam Nguyen
- Yoonsik Yi
Organizations
- Chonnam National University
- Defense Advanced Research Projects Agency
- Electronics and Telecommunications Research Institute
- Korea Institute of Energy Technology Evaluation and Planning
- Korea University of Science and Technology
- National Research Foundation of Korea
- Semiconductor Research Corporation
- University of Texas at Dallas