Band gap and interface engineering of ZnO@MoSe2heterojunction film and its light-matter coupling

Abstract

The wide/narrow band gap semiconductor heterojunction promotes the coupling of light with matter and the rapid electron transport, which opens up a new research way for the construction of heterojunctions, photodetectors and quantum phenomena due to their excellent optical properties. Hereon, petal-like ZnO@MoSe2 and worm-like MoSe2 films were prepared by two-step/single-step RF magnetron sputtering method. Combined with the experimental results and the finite difference time domain (FDTD) simulation, it is proven that the 1T and 2H mixed phase MoSe2 can provide low energy growth sites for ZnO. ZnO@MoSe2 longitudinal n-p heterojunctions can form super-fast carrier transfer channels, enhancing the luminescence properties of heterojunctions in near-Gaussian fields. Moreover, both MoSe2 and ZnO@MoSe2 films show saturation absorption phenomenon with the coefficients of 0.43 × 10−7 mW−1 and 0.18 × 10−7 mW−1, respectively. The saturation absorption coefficient of ZnO@MoSe2 films is reduced due to Pauli blocking, which is caused by the electron transfer from the conduction band of MoSe2 to the conduction band of ZnO. The synthesized ZnO@MoSe2 films can be used in all optical switching, passive mode locking and other fields.