Modified structures of multicrystalline silicon as light detectors

Photovoltaic structures of multicrystalline silicon were modified by the deposition of a-Si:C:H thin films. The films have been deposited by Plasma Enhanced Chemical Vapor Deposition at 13.56 MHz in SiH4 +CH4 gaseous mixtures. The structures have been investigated by means of optical and electrical methods. Spectral photosensitivity measurements were done at room temperature in voltage and current modes. The signal was registered in the function of light in the visible and near infrared region from 400 to 1100 nm. Silicon structures covered by a-Si:C:H have higher spectral photosensitivities than uncover ones and the apparent increase in efficiency has been observed.