SILICON-CARBIDE UV PHOTODIODES

SiC photodiodes were fabricated using 6H single-crystal wafers. These devices have excellent UV responsivity characteristics and very low dark current even at elevated temperatures. The reproducibility is excellent and the characteristics agree with theoretical calculations for different device designs. The advantages of these diodes is that they will operate at high temperatures and are responsive between 200 and 400 nm and not responsive to longer wavelengths because of the wide 3-eV bandgap. The responsivity at 270 nm is between 150 and 175 mA/W with a quantum efficiencies of between 70% and 85%. Dark-current levels have been measured as a function of temperature that are orders of magnitude below those previously reported. Thus these diodes can be expected to have excellent performance characteristics for detection of low light level UV even at elevated temperatures.