Theoretical prediction of a high-performance two-dimensional type-II MoSi2N4/As vdW heterostructure for photovoltaic solar cells

Abstract

Solar cells are expected to become one of the dominant electricity generation technologies in the coming decades. Developing high-performance absorbers made from thin materials is a promising pathway to improve efficiency and reduce cost, accelerating the widespread adoption of these photovoltaic cells. In the present work, we have systematically investigated the 2D MoSi 2 N 4 /Arsenene van der Waals (vdW) heterostructure, which exhibits a type-II band alignment with an indirect band gap semiconductor (1.58 eV), can effectively separate the photogenerated electron–hole (e − –h + ) pairs and and suitability for practical applications in challenging environments. Compared to the isolated MoSi 2 N 4 and Arsenene monolayers, the optical absorption strength can be significantly enhanced in MoSi 2 N 4 /Arsenene vdW heterostructure (in the order of ∼ 10 5 cm −1 in the visible region). The calculated optical absorption gaps are 2.12 eV (arsenene) and 1.76 eV (MoSi 2 N 4 ), with excitonic binding energies of 0.05 eV for arsenene and 0.48 eV for MoSi 2 N 4 , indicating that both materials can effectively form excitons and separate charges. Moreover, we found a high spectroscopic limited maximum efficiency of 27.27% for the MoSi 2 N 4 /Arsenene vdW heterostructure, which is relatively higher compared to previously reported 2D heterostructures. Ab-initio molecular dynamics (AIMD) simulations at 300 K, 600 K, and 900 K were conducted to evaluate the thermal stability of the MoSi 2 N 4 /Arsenene heterostructure. Simulations in the presence of water and NO 2 at 300 K were also performed to assess its resilience to humidity and pollutants. The results suggest strong stability under harsh environmental conditions. Our findings demonstrate that the 2D MoSi 2 N 4 /Arsenene vdW heterostructure is an excellent candidate for both photovoltaic device applications and optoelectronic nanodevices. • 2D MoSi 2 N 4 /Arsenene vdW is highly stable with type-II band alignment (E g =1.58 eV). • Effectively creates e − –h + pairs due to large difference in e − & h + effective mass. • It shows significantly enhanced optical absorption compared to its pristine sheet. • Electrostatic potential difference of 0.28 eV induces spontaneous charge transfer. • Predicted efficiency 27.27% shows ideal for high-performance photovoltaic applications.

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