Thin-film photodetectors for the ultraviolet and vacuum-ultraviolet spectral range

摘要

In this paper we report about thin film photodetectors optimized for the detection of the vacuum ultraviolet. The devieces are based on hydrogenated amorphous silicon and silicon carbide p-i-n heterostructures on glass substrate. At room temperature the photodetectors exhibit values of quantum efficiency of 52 percent at #lambda#=58.4 nm, 1percent at #lambda#=400 nm, and 0.1percent at #lambda#=650 nm. The time response at ultraviolet pulses from an N_2 laser gives signals with 6 #mu#s full width half maximum and 500 ns rise time. Stability of the device is presently affected by light activation of boron dopant occurs in the p-layer under U V illumination and ihas been investigated by a simple equivalent circuit of the structure. The effect can be minimized by optimization on the electrode geomery. The devices are suitable for integration in low-cost, large-area arrays.