Biaxial strain and electric field modulated band alignment and optical properties of the MoTe2/SnC van der Waals heterostructure.

Based on first-principles calculations, we comprehensively investigate the geometric structure, electronic and optical properties of the MoTe2/SnC Van der Waals heterostructure (vdWH). Six distinct stacking configurations of the MoTe2/SnC vdWH are constructed based on various alignment methods. A3 configuration behaves type-I band alignment, while the other five configurations show type-II alignment. The most stable B2 configuration exhibits type-II band alignment with a direct band gap of 0.85 eV. Biaxial strain and electric fields induce the transition from direct to indirect bandgap semiconductors, and enable rapid conversion from type-II to type-I band alignment. The heterostructure achieves a peak optical absorption coefficient of 24%. Both the absorption intensity and spectral absorption range can be effectively tuned by applying biaxial strain and electric fields. The theoretical power conversion efficiency is up to 13.10%. The present results suggest a possible theoretical framework for high-performance optoelectronic applications of the MoTe2/SnC vdWH.