Two-dimensional XYN3 (X=V, Nb, Ta; Y=Si, Ge): Promising optoelectronic materials in photovoltaic photodetectors

Abstract

Two-dimensional p-type/intrinsic/n-type (p-i-n) homojunction opens up exciting opportunities for the advancement of next-generation electronic and optoelectronic devices. However, it is urgent to explore superior two-dimensional materials for p-i-n homojunction to enhance optoelectronic performance. Herein, the electronic structures, optical properties of monolayer XYN3 (X=V, Nb, Ta; Y=Si, Ge), and the related p-i-n homojunctions are constructed and investigated systematically based on the framework of density function theory and non-equilibrium Green's function calculations. The electronic structures and optical absorption of these stable monolayers reveal that they show semiconductor characteristic with indirect bandgaps of 1.23∼2.13 eV, which possess strong absorption of visible light. The simulations of the p-i-n homojunctions based on these monolayers highlight that VSiN3 and TaSiN3-based p-i-n junctions possess maximum photocurrent densities of 21.43 and 18.48 A/m2, respectively. Moreover, the photoresponses of VSiN3 and TaSiN3-based p-i-n junctions can reach up to 0.61 and 0.55 A/W, respectively, demonstrating that VSiN3 and TaSiN3-based p-i-n junctions could be the ideal candidates for optoelectronic devices. Our work is expected to pave the way for the realization of 2D p-i-n homojunction optoelectronic devices.