Research on interface properties of InGaAs photocathode with nanowire structure

InGaAs photocathode with nanowire structure is studied by first-principles approach. The nanowire-structured InGaAs photocathodes with GaAs or InP substrate are compared from three aspects: lattice structure, electronic structure and optical properties. Interfaces of In0.5Ga0.5As-GaAs and In0.5Ga0.5As-InP are focused on research. In order to better describe the optical properties, the light reception on the side of InGaAs nanowires is also analyzed. Crystal structures close to the two sides of interfaces are both relaxed. Electronic structure and optical properties shows that the photocathode with GaAs substrate is more beneficial to the absorption of light in the near-infrared band. In additional the electric field distribution at the interface promote the transition of photoelectrons. Thereby the photoemission efficiency of the photocathode is improved.