4H-SiC metal–semiconductor–metal ultraviolet photodetectors with Ni/ITO electrodes

Indium–tin-oxide (ITO), Ni/ITO and Ni layers were deposited onto glass and/or SiC substrates by DC sputtering under different deposition conditions. SiC-based metal–semiconductor–metal (MSM) ultraviolet (UV) photodetectors were also fabricated using these materials as contract electrodes. It was found that ITO film deposited without oxygen gas could provide us a better optical property and a better electrical property. It was also found that the dark current of the ITO/SiC MSM UV photodetector was extremely large. Furthermore, it was found that the insertion of a 10 nm Ni layer could significantly reduce the dark current. It was also found that the photo-current to dark current contrast was more than 3 orders of magnitude with a 5 V applied bias for the SiC MSM UV photodetector with 10 nm Ni/90 nm ITO contact electrodes. With an even larger 40 V applied bias, the photo-current to dark current contrast could almost reach 4 orders of magnitude.