Sb2TeSe2 Monolayers: Promising 2D Semiconductors for Highly Efficient Excitonic Solar Cells

Chun Wang; Yu Jing; Xiaocheng Zhou; Ya-Fei Li

doi:10.1021/acsomega.1c02746

Sb₂TeSe₂ Monolayers: Promising 2D Semiconductors for Highly Efficient Excitonic Solar Cells

ACS Omega. 2021 Jul 27;6(31):20590-20597. doi: 10.1021/acsomega.1c02746. eCollection 2021 Aug 10.

Authors

Chun Wang¹, Yu Jing², Xiaocheng Zhou¹, Ya-Fei Li¹

Affiliations

¹ Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China.
² Jiangsu Co-Innovation Centre of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.

Abstract

On the basis of density functional theory computations, we demonstrated that two-dimensional (2D) α- and β-Sb2TeSe2 monolayers are promising candidates for constructing high-efficiency heterojunction excitonic solar cells. These two 2D materials possess moderate band gaps (∼1.1 eV), which can be flexibly tuned by applying external strains. They possess high carrier mobility (∼3000 cm² V^-1 s^-1) and can absorb sunlight over the whole range of the solar spectrum. Remarkably, the α- and β-Sb2TeSe2 monolayers can form desirable type II heterostructures with HfSe2 and BiOI monolayers, respectively. The power conversion efficiencies of α-Sb₂TeSe₂/HfSe₂ and β-Sb₂TeSe₂/BiOI heterojunction excitonic solar cells can reach 22.5 and 20.3%, respectively. Since α-Sb2TeSe2 and β-Sb2TeSe2 monolayers have good stability and high synthesis feasibility, they have important applications in photovoltaic solar cell devices.