High-Performance 4H–SiC-Based Metal–Insulator–Semiconductor Ultraviolet Photodetectors With $\hbox{SiO}_{2}$ and $\hbox{Al}_{2}\hbox{O}_{3}\hbox{/}\hbox{SiO}_{2}$ Films

4H-SiC-based metal-insulator-semiconductor (MIS) ultraviolet (UV) photodetectors with thermally grown SiO
₂
and evaporated Al
₂
O
₃
/SiO
₂
(A/S) films are fabricated and demonstrated as normally-off and normally-on mode devices, respectively. Ultralow dark currents of 3.25 × 10
^-10
and 9.75 × 10
^-9
A/cm
²
and high UV-to-visible rejection ratios of >; 2 × 10
³
have been achieved at 10 V. The peak responsivities of these devices were separately 30 mA/W at 260 nm and 50 mA/W at 270 nm at 10 V. These results demonstrate that S/4H-SiC and A/S/4H-SiC MIS photodetectors are promising candidates to be applied in optoelectronic integrated circuits.