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.