Characterization of GaN based Schottky UV detectors in the vacuum UV (VUV) and the soft X-ray (SX) region (10-100 nm)

Abstract

Responsivity spectra of GaN based Schottky type ultraviolet (UV) photodetectors with transparent electrode from the Vacuum Ultraviolet (VUV) region to soft X-ray (SX) region (10-100 nm, 124-12.4 eV) are described for the first time. The calculated transmittance of 10 nm-thick transparent Ni/Au electrode from the transmittance of Ti/Au membrane is about 0.5-0.7 in the VUV and SX region (10-100 eV). Thus it is considered that the 10-nm-transparent Ni/Au electrode is thin enough to transmit VUV and SX light into the transparent electrode. The value of responsivity in the SX region (at 13 nm) is about 0.05 A/W