OPTICAL CONTRAST FORMATION IN A-SI1-XCX-H FILMS BY ION-IMPLANTATION

The formation of optical contrast in a-Si1-xCx:H alloy films by ion implantation with Ar and group IV elements has been investigated. The increased disorder and additional chemical modification of a-Si1-xCx:H, induced by the implantation of Ge or Sn, results in a considerable change of the optical properties. Darkening of the implanted films, demonstrated by absorption edge shift to the lower photon energies, has been registered, varying with the dose, implanted element and alloy composition. The accompanying change in the optical gap and absorption coefficient has been derived from the transmission, reflection and PDS (photodeflection spectroscopy) measurements.