Simulated h-BP/MoSe₂ Photonic Heterostructure with High Optoelectronic Transduction Efficiency

The rise of two-dimensional (2D) materials unfolds directions for ultrathin, high-quality, and efficient heterojunction-based solar cells. In this study, through first-principles density functional theory computations, we investigated the optoelectronic features of 2D hexagonal boron phosphide/molybdenum diselenide (h-BP/MoSe2) van der Waals heterostructures (vdWHs). The designed pristine heterostructure is thermally and energetically stable having type I band alignment with a direct bandgap (0.994 eV). The studied heterostructure exhibits an impressive absorption coefficient peak of 2.84 × 105 cm–1 at 688.8 nm. Furthermore, we analyzed the impact of uniaxial and biaxial strain on the optical characteristics of h-BP/MoSe2 vdWHs. The strain-tuned h-BP/MoSe2 vdWHs demonstrate a transition from type I to type II band alignment. A significant increase in the absorption coefficient peak (3.65 × 105 cm–1) was observed upon the application of tensile strain. The maximum power conversion efficiency (MPCE) of 29.7% suggests that the studied heterostructure has the potential to be used for 2D excitonic solar cells under strain conditions. The findings of this study demonstrate the capability of h-BP/MoSe2 vdWHs as a flexible platform for the design of highly efficient 2D solar cells and light-emitting devices.