Jump to main content
Jump to site search


A type-II GaSe/GeS heterobilayer with strain enhanced photovoltaic properties and external electric field effects

Author affiliations

Abstract

Constructing two dimensional (2D) van der Waals (vdW) heterostructures and understanding their electronic properties are pivotal for developing novel electronic devices. In this work, by using the first-principles calculations, we theoretically demonstrate that the 2D GaSe/GeS van der Waals (vdW) heterobilayer is a robust type-II band alignment semiconductor with a direct band gap of 1.8 eV. It exhibits a remarkable absorbance coefficient of ∼105 cm−1 from the UV to visible light region and a high carrier mobility with anisotropic character. The photoelectric conversion efficiency (PCE) shows a tremendous enhancement under external strain, and shows an efficiency of up to ∼16.8% at 2% compressive strain. Besides, we find that applying an external electric field can effectively modulate its band gap and band offset. Interestingly, a larger external electric field can induce nearly free electron (NFE) states around the conduction band minimum (CBM) in the GaSe/GeS heterobilayer, which leads to the band transition from a semiconductor to metallic status. These results indicate that 2D GaSe/GeS heterostructures will have widespread application prospects in future photovoltaic and optoelectric nanodevices.

Graphical abstract: A type-II GaSe/GeS heterobilayer with strain enhanced photovoltaic properties and external electric field effects

Back to tab navigation

Supplementary files

Publication details

The article was received on 25 Oct 2019, accepted on 29 Oct 2019 and first published on 30 Oct 2019


Article type: Paper
DOI: 10.1039/C9TC05840K
J. Mater. Chem. C, 2019, Advance Article

  •   Request permissions

    A type-II GaSe/GeS heterobilayer with strain enhanced photovoltaic properties and external electric field effects

    B. Zhou, S. Gong, K. Jiang, L. Xu, L. Shang, J. Zhang, Z. Hu and J. Chu, J. Mater. Chem. C, 2019, Advance Article , DOI: 10.1039/C9TC05840K

Search articles by author

Spotlight

Advertisements