GAN-BASED SOLAR-ULTRAVIOLET DETECTION INSTRUMENT

We report on the fabrication of a solar-UV monitoring system that uses GaN-based photodetectors. GaN photoconductors, p-n junction photodiod es, and Schottky barrier photodiodes have been fabricated and characte rized as UV sensors. The best performances are obtained in Schottky ph otodiodes, which show a linear response, a fiat responsivity of 100 mA /W, a visible rejection ratio higher than 10(3), and a noise-equivalen t power of 1 nW/Hz(-1/2). Preliminary data on AlxGa1-xN (x = 0.15, 0.2 2) detectors are also presented. Using GaN Schottky diodes, we fabrica te and evaluate a complete solar-UV detection head. (C) 1998 Optical S ociety of America.