상세정보
학술지
Bandgap Tuned WS2 Thin-Film Photodetector by Strain Gradient in van der Waals Effective Homojunctions
- 발행일
- 202111
- 출처
- Advanced Optical Materials, v.9 no.22, pp.1-10
- ISSN
- 2195-1071
- 출판사
- Wiley
- 협약과제
- 21PB4200, 0.5gpm미만의 원자로냉각재계통 미확인 누설 실시간 감시시스템 개발, 최춘기
- 초록
- 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.
- KSP 제안 키워드
- 2D material, 2D semiconductors, Electronic structures, Hexagonal boron nitride(h-BN), High performance, Hole carriers, Strain gradient, Sulfurization method, Transmission Electron Microscopy(TEM), Type-II heterojunction, Van der Waals (vdW) heterostructures