Time-resolved spectroscopy of luminescence in a wide gap Si-doped -Ga2O3

Optical properties of Si-doped -Ga2O3 have been investigated by the time-resolved spectroscopy, as well as by the conventional cw-spectroscopy. The green photoluminescence is observed for photo-excitations below the optical band gap E-g. The excitation spectrum of the green photoluminescence indicates a weak absorption band, presumably induced by Si-doping, located at 0.2-0.3eV below the conduction band minimum. The time-resolved spectroscopy has revealed that the green photoluminescence manifests itself as the slower decay component. On the other hand, the fastest decay component, which is distributed from the UV to green regions, can be characterized by a time constant of approximate to 100ns, comparable to that for un-doped -Ga2O3.