Large area GaN Schottky photodiode with low leakage current

Pt/n-type GaN Schottky photodiodes with large active areas which exhibit low leakage currents are fabricated. Reverse bias leakage currents of 2.7 nA for a 1 cm/sup 2/ diode and 14 pA for a 0.25 cm/sup 2/ diode both at -0.5 V bias are reported. External quantum efficiency measurements between the spectral range 50 to 500 nm gave a peak responsivity of 77.5 mA/W at 320 nm for a 0.25 cm/sup 2/ diode, corresponding to a spectral detectivity, D*=1.5*10/sup 14/ cmHz/sup 1/2/ W/sup -1/.