Thin-film photodetectors for the vacuum ultraviolet spectral region

We report on thin-film photodetectors optimized for detecting the vacuum UV and rejection of the visible spectrum of electromagnetic radiation. The devices are made of hydrogenated amorphous silicon and silicon carbide on a glass substrate. At room temperature the photodetectors exhibit quantum efficiencies of 52% at lambda = 58.4 nm, 1% at lambda = 400 nm, and 0.1% at lambda = 650 nm. The response time for UV pulses from an N-2 laser gives signals of 6-mu s full width at half-maximum and 500-ns rise time. (C) 1997 Optical Society of America.