(InxGa1−x)2O3 Photodetectors Fabricated on Sapphire at Different Temperatures by PLD

The (In
_x
Ga
_1−
x
)
₂
O
₃
photodetectors were fabricated on the single-crystalline (In
_x
Ga
_1−
x
)
₂
O
₃
films deposited on sapphire substrate by pulsed laser deposition. The structural and optical properties of the epilayers were investigated using high-resolution X-ray diffraction, X-ray photoelectron spectroscopy, spectroscopic ellipsometry, and transmittance spectra. With decreasing the growth temperature, the indium composition increased and the bandgap decreased from 4.99 eV to 4.89 eV (In
_0.05
Ga
_0.95
)
₂
O
₃
and 4.78 eV (In
_0.08
Ga
_0.92
)
₂
O
₃
. Furthermore, the photoelectrical characteristics of (In
_x
Ga
<sub>1−

x</sub>
)
₂
O
₃
detectors were also studied. The enhanced
$I_{{\text{photo}}}$
,
$I_{{\text{dark}}}$
, and responsivity
R
were achieved in the devices with higher In composition, while a larger number of defects were introduced, resulting in the significant persistent photoconductivity.