High Performance β-Ga2O3 Solar-Blind Metal–Oxide–Semiconductor Field-Effect Phototransistor with Hafnium Oxide Gate Dielectric

This letter demonstrates a high performance β-Ga2O3 solar-blind metal–oxide–semiconductor field-effect phototransistor (SBPT) with Hafnium Oxide (HfO2) Gate Dielectric. The SBPT shows a high Photo-to-dark-current ratio (PDCR) of 6.9×107, an I254nm/I365nm rejection ratio of 6.0×107 combined with an external quantum efficiency (EQE) of 6.4×107 %. In addition, benefit from stronger control capability of the HfO2 based gate structure, the fabricated SBPT reaches a record detectivity (D*) of 1.1×1019 Jones and ultrahigh responsivity (R) of 1.4×107 A/W. Furthermore, short decay time (τd) is obtained to be as low as 16 ms. These outstanding properties indicate that SBPT is promising for the solar-blind detection.