Microdoped and microcompensated amorphous silicon films for infrared detection

In this letter, we demonstrate detection at room temperature of near and medium infrared (IR) radiation by using microdoped and microcompensated amorphous silicon as a separation layer in a p-n junction. The IR absorption in the 800-4600-nm wavelength range is due to the high density of trap states induced by the dopant impurities. In particular, we argue that detection in the medium IR range involves localized states near the valence band associated with boron doping. Detection of near-infrared (NIR) radiation can be related, instead, to localized states near the conduction band caused by distortion of the amorphous network due to the very low concentration of phosphorous and boron.