High-Performance β-Ga₂O₃-Based Solar-Blind Metal–Oxide–Semiconductor Field-Effect Phototransistor Under Zero Gate Bias

In this work, a high-performance $\beta $ -Ga ₂ O ₃ -based solar-blind metal–oxide–semiconductor field-effect phototransistor (SBPT) is demonstrated. SBPT exhibits excellent photoelectrical properties when the gate voltage ( ${V}_{\text {GS}}$ ) bias is at 0 V, including a large photo-dark current ratio ( PDCR ) of 1.5 $\times \,\,10^{{6}}$ , a high responsivity ( ${R}$ ) of 1.3 $\times \,\,10^{{7}}$ A/W, a large external quantum efficiency (EQE) of 6.4 $\times \,\,10^{{7}}$ % and a high detectivity ( ${D}^{\ast }$ ) of 4.8 $\times \,\,10^{{18}}$ Jones. Decay time ( $\tau _{d}$ ) is extracted to be 454 ms. The ultrahigh photoresponse performance of the device illustrates that SBPT working at the gate bias of 0 V provides a potential route for the application of solar-blind photodetector (SBPD).