GaN homojunction and AlGaN/GaN heterojunction visible-blind photodiodes grown on SiC

GaN homojunction and AlGaN/GaN heterojunction UV photodiodes were successfully fabricated and tested. The p + /n mesa devices were grown on a n-type 6H-SiC substrate. Photoresponse was observed in these deices from 206 nm to the cutoff wavelength of GaN. Peak responsivity values of 111 mA/W and 123 mA/W were observed at 360 nm for unpackaged homojunction and heterojunction devices, respectively. In packaged device, the peak responsivity increased to 124 and 147 mA/W for the homojunction and heterojunction devices, respectively. High breakdown voltages in excess of 100 V for the homojunction and 70 V for the heterojunction devices were obtained with dark current densities of 3 by 10 -11 A/cm 2 and 1 by 10 -10 A/cm 2 A/cm 2 at -1V bias at room temperature, respectively. These result show that homojunction and heterojunction visible-blind detectors can be fabricated in the AlGaN/GaN material system on SiC substrates.