D. Caputo et al., MICRODOPED AND MICROCOMPENSATED AMORPHOUS-SILICON FILMS FOR INFRARED DETECTION, IEEE photonics technology letters, 10(8), 1998, pp. 1147-1149
In this letter, we demonstrate detection at room temperature of near a
nd medium infrared (IR) radiation by using microdoped and microcompens
ated 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 den
sity of trap states induced by the dopant impurities. In particular, w
e argue that detection in the medium IR range involves localized state
s near the valence band associated with boron doping. Detection of nea
r-infrared (NIR) radiation can be related, instead, to localized state
s near the conduction band caused by distortion of the amorphous netwo
rk due to the very low concentration of phosphorous and boron.