Spectral response design of hydrogenated amorphous silicon p-i-n diodes for ambient light sensing

For the applications involving ambient light sensing, the spectral response of photodetectors is required to mimic that of human eyes and the cost must be low. This paper discusses the layer structure design of human-eye-like hydrogenated amorphous silicon (a-Si:H) p-i-n photodiodes. The resultant sample devices are insensitive to infrared light and have a normal spectral response in the light band ranging between 400 nm wavelength and 740 nm wavelength. The spectrum peak locates around 560 nm wavelength, similar to the case of human eyes. The devices are suitable for low-cost ambient light sensing applications.