Characterization of GaN Based UV-VUV Detectors in the Range 3.4-25 eV by Using Synchrotron Radiation

The characterization of Schottky type ultraviolet (UV) detectors with transparent electrode between vacuum ultraviolet (VUV) and visible light region using synchrotron radiation is described. The responsivity spectrum of the detectors at 0 V bias was obtained in the wide range between 2 eV (563 nm) and 25 eV (50 nm). The photoemission current from Au electrode was able to be canceled by improving the measuring circuit, and thus we succeeded in operating the detectors without any photoemission current from Au and GaN. The responsivity of the detectors is about 0.15 A/W at 3.5 eV. These results show that these Schottky type detectors with the transparent electrode are effective to detect VUV-UV light (50–360 nm, 3.4–25 eV) without any photoemission.