Heterostructures stacked with X2SY (X = In, Ga; Y = Se, Te) and g-C2N monolayers for high power conversion efficiency solar cells: insight from electronic properties and nonadiabatic dynamics

Abstract

Three heterostructures stacked with Janus group-III chalcogenides (X₂SY; X = In, Ga and Y = Se, Te) and g-C₂N monolayers are screened for solar cells based on the calculated electronic properties, optical absorption, power conversion efficiency, and nonadiabatic molecular dynamics (NAMD) simulations. A total of 114 different configurations of 14 heterostructures from the various stacking models of X₂SY and g-C₂N monolayers are considered. The power conversion efficiencies of the Ga₂STe/In₂STe, g-C₂N/Ga₂STe, and g-C₂N/In₂STe heterostructures with optimal stacking patterns are 14.06%, 10.01%, and 11.30%, respectively. Moreover, the power conversion efficiency of Ga₂STe/In₂STe can be enhanced to 20.79% under −4% compressive biaxial strain. The NAMD results demonstrate that all three heterostructures have a short interlayer carrier transfer time and a long electron–hole recombination time, which supports the high efficiency of carrier utilization in these heterostructures. Moreover, the long electron–hole recombination process and short electron/hole transfer process for g-C₂N/In₂STe are favorable for achieving a high power conversion efficiency. Therefore, this heterostructure is a promising material in the applications of solar cells.