Diamond film ultraviolet detectors with different diamond grain size

Abstract

Diamond films with different grain sizes from 1.8 μm to 3.1 μm were prepared using the bias-enhanced hot-filament chemical vapor deposition (HFCVD) technique. The film structure and morphology were characterized using the optical microscope and Raman spectrometer. Ultra-violet (UV) detectors with interdigital patterns were fabricated using above diamond films. I-V measurement results showed that the performance of the detector was closely related with the grain size of the diamond film. With increasing the grain size, the photo-current, the ratio of photo-current to dark-current and the net photo-current all increased. The above results indicate that diamond films with larger grain size are more suitable for being fabricated as UV detectors. © 2009 IOP Publishing Ltd.