Infrared photodetection at room temperature using photocapacitance in amorphous silicon structures

In this letter we present a device, based on amorphous silicon material, able to detect infrared light through capacitance measurement at room temperature. The device is a p-c-n stacked structure, where c indicates a compensated amorphous silicon absorber layer. Operation is based on transitions between extended states in the valence band and defects in the forbidden gap excited by the infrared radiation. We found that the measured capacitance is sensitive to radiation from 800 nm to 5 μm.