UV photodetector from Schottky diode diamond film

Abstract

Diamond film was synthesized on a silicon substrate by hot-filament CVD and used to fabricate a Schottky photodiode for the detection of UV light. This paper presents an improved structure of photodiode, which reduces the effect of grain boundaries in the polycrystalline diamond film. The Schottky photodiode was fabricated on free-standing diamond film and operation in a vertical direction can be expected to reduce the effect of grain boundaries. The device shows good response to UV light and a very low response to visible light. The dark current is less than 10 pA. The device response time is less than 20 μs. Furthermore, the device reveals little change in spectral response with increasing temperature at all wavelengths. © 2002 Elsevier Science B.V. All rights reserved.