High-sensitivity Solar-blind photodetector based on Ga2O3 films through manipulating oxygen vacancies

Oxygen vacancies (VO’s) play an extremely important role in the internal gain and the persistent photoconductivity (PPC) effect of metal–semiconductor-metal (MSM) Ga2O3 photodetectors (PDs). The VO’s of bulk phase and interfacial can be manipulated by the annealing process. Herein, the annealing of amorphous-Ga2O3 (a-Ga2O3) film can significantly reduce the VO’s of the bulk phase, so the PDs can exhibit faster response speed due to the suppression of the PPC effect. The VO’s at the interface of M/S can be introduced by the device post-annealing. As a result, responsivity (R) and specific detectivity (D*) were greatly improved, reach to 54.0 A/W, and 2.17 × 1014 Jones, respectively. The increased specific internal gain at the interface of M/S should be responsible for the improvement of sensitivity.