High-Performance β-Ga2O3 Solar-Blind Photodetector with Extremely Low Working Voltage

The Ga 2 O 3 solar-blind photodetectors (SBPDs) face the tradeoff between power consumption ( $P_{\text {C}}$ ) and photoresponse performance. Here, an ultrasensitive two-terminal photodetector based on $\boldsymbol {\beta }$ -Ga 2 O 3 microflake with extremely-low working voltage and ${P}_{\text {C}}$ was achieved. At a working voltage of 2 V and ${P}_{\text {C}}$ of 10 fW, the Ga 2 O 3 SBPD exhibits superexcellent photodetection performance, including a responsivity ( ${R}$ ) of ${2.3}\,\,\times \,\,{10}^{{5}}\text{A}$ /W, a detectivity ( ${D}^{ \boldsymbol {\ast }}$ ) of ${3.5}\,\,\times \,\,{10}^{{18}}$ Jones, a photo-to-dark-current ratio ( PDCR ) of ${3.2}\,\,\times \,\,{10}^{{8}}$ , and an ultra-low dark current ( ${I}_{\text {dark}}$ ) of 5 fA. Strikingly, the device keeps satisfactory performance at ultralow working voltage of 0.01 V, including a ${P}_{\text {C}}$ of 0.05 fW, a ${R}$ of ${2.4}\,\,\times \,\,{10}^{{3}}$ A/W, a ${D}^{ \boldsymbol {\ast }}$ of ${5.6}\,\,\times \,\,{10}^{{16}}$ Jones, and a PDCR of ${3.4}\,\,\times \,\,{10}^{{6}}$ . The superior solar-blind sensitivity makes it the most excellent Ga 2 O 3 detector towards high-performance and low- $P_{\text {C}}$ SBPD applications.