Intrinsic electric field regulated photoexcited charge carrier transfer at the interface of GeC/MoSSe heterostructure

Abstract Combining first-principles calculations and nonadiabatic (NA) molecular dynamics simulations, this study explores the electronic structures, optical properties and photoexcited charge carrier dynamics in GeC/MoSSe with two stacking configurations. Electrostatic potential analysis demonstrates stacking-dependent interfacial electric fields in the heterostructures. Notably, the type-II GeC/SMoSe heterolayer exhibits an electric field that promotes ultrafast charge separation with electron and hole transfer time of 68 fs and 40 fs, respectively, via multiple intermediate electronic states serving as efficient transfer channels. Moreover, electron–hole recombination time in GeC/SMoSe is prolonged to 94.2 ns, nearly seven times as long as that of GeC/SeMoS, which originates from reduced NA coupling and enhanced decoherence. These findings reveal the critical role of Janus asymmetry-induced interfacial electric fields in tailoring charge carrier dynamics in van der Waals heterostructures for promising applications in optoelectronics.