Highly stable two-dimensional Janus Transition Metal Dichalcogenide-Based van der Waals heterostructures for exceptional solar cell performance

Abstract

The development and utilization of solar energy are extremely important for alleviating energy and environmental problems. Herein, we comprehensively fabricated a series of two-dimensional Janus MXY-based van der Waals heterostructures (M=Mo, W; X, Y=S, Se, Te, and X≠Y) and thoroughly investigated their potential applications in solar cells using first-principles density functional theory. Further analysis identifies 20 heterostructures with power conversion efficiencies (PCEs) exceeding 20 %. Additionally, the impact of spin-orbit coupling (SOC) effects and intrinsic dipole correction on band structures and PCEs is examined. Particularly noteworthy are the WSSe/WSeTe SeSe BB and WSeTe/WSTe TeTe BB' vdWHs, exhibiting superior PCEs of 19.25 % (23.51 %) and 21.53 % (20.49 %) with (without) SOC effects and dipole correction, alongside minimal exciton binding energies (0.36 and 0.32 eV), excellent stability, and high light absorption coefficients (105∼106 cm−1). These outstanding values surpass most reported results. These findings underscore the potential of Janus transition metal dichalcogenide (TMD) vdWHs, particularly WSSe/WSeTe SeSe BB and WSeTe/WSTe TeTe BB' configurations, for advanced solar cell applications, offering valuable theoretical insights for future experimental investigations.