M-Plane α-Ga₂O₃ Solar-Blind Detector With Record-High Responsivity-Bandwidth Product and High-Temperature Operation Capability

We report on high-performance solar-blind photodetectors fabricated on the m-plane
$\alpha $
-Ga
₂
O
₃
epilayer grown by laser molecular beam epitaxy using the segment target approach. Benefited from the improved epitaxial quality with an
$\alpha $
-(Al
_0.24
Ga
_0.76
)
₂
O
₃
intermediate layer, the
$\alpha $
-Ga
₂
O
₃
detector shows a low dark current of 0.23 pA, a UV/visible rejection ratio of over
$10^{{5}}$
, a photo-to-dark-current ratio of
${4.4}\times {10}^{{7}}$
, a peak responsivity of 132.6 A/W, a short response time of 97
$\mu \text{s}$
, and a specific detectivity of
${1.23}\times {10}^{{15}}$
Jones at the bias of 10 V. High-temperature operation robustness is also demonstrated up to 423 K, exhibiting the reduction of dark current, a maintained high responsivity (33.9 A/W) and a speedy response (90
$\mu \text{s}$
), which is on the frontier among the state-of-the-art Ga
₂
O
₃
solar-blind detectors with a record-high responsivity-bandwidth product. The temperature-dependent transient photocurrent feature implies that high gains result from the enhanced carrier lifetime due to the surface bending. It suggests that the m-plane
$\alpha $
-Ga
₂
O
₃
detectors are promising for real-time monitoring to high-speed objectives with weak radiation flux in harsh environments.