Design, fabrication and characterization of an a-Si: H-based UV detector for sunburn applications

A thin-film alpha-Si: H pin detector was developed for selective detection of UVA (320 - 400 nm) radiation. In order for the fabrication technology to be transferable onto flexible substrates, all of the processing steps were conducted at temperatures less than 125 degrees C. The measured saturation current as low as 2 pA cm(-2) and the ideality factor of 1.47 show that the pin diodes have a good quality i-layer as well as p-i and n-i interfaces. The film thicknesses were optimized to suppress the detector sensitivity in the visible spectral range, and the peak of spectral response was observed at 410 nm. The selectivity estimated from the ratio of the photocurrent generated by UVA absorption to the total photocurrent is 21%.