The hot carrier dynamics of graphitic carbon nitride/molybdenum disulfide heterojunctions

Abstract

We perform nonadiabatic molecular dynamics to investigate the relaxation of the excited electrons and holes in g-C3N4/MoS2 heterojunctions. The results indicate that the hot carriers relaxation dynamics strongly depend on the nonadiabatic coupling, band gap and pure-dephasing time. We choose hot electrons and hot holes excited to different energy states with similar excess energies ΔE ≈ 0.42 eV, and hot electrons and hot holes relax to lower energy states with the time scales 0.57 ps and 0.23 ps. Stronger nonadiabatic coupling and slower pure-dephasing time accelerate the hot holes transfer. In general, it is found that the hot holes decay faster than hot electrons, because the couplings between the holes states in the valence band are stronger than the electrons states in the conduction band.