High-Performance 4H-SiC-Based Metal-Insulator-Semiconductor Ultraviolet Photodetectors With SiO2 and Al2O3/SiO2 Films

4H-SiC-based metal-insulator-semiconductor (MIS) ultraviolet (UV) photodetectors with thermally grown SiO2 and evaporated Al2O3/SiO2 (A/S) films are fabricated and demonstrated as normally-off and normally-on mode devices, respectively. Ultralow dark currents of 3.25 x 10(-10) and 9.75 x 10(-9) A/cm(2) and high UV-to-visible rejection ratios of > 2 x 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.