J. Phys. IV France 05 (1995) C5-1109-C5-1115
Plasma-Enhanced Chemical Vapour Deposition of Amorphous Se FilmsP. Nagels, E. Sleeckx and R. Callaerts
RUCA, University of Antwerp, 2020 Antwerpen, Belgium
The preparation of layers of amorphous Se by plasma-enhanced CVD using the hydride H2Se as precursor gas is described. Using a mixture of 15 vol.% H2Se in H2, partly crystallized films were obtained. Information concerning the structure of the films was obtained from Raman spectroscopy. The spectra of amorphous Se indicated that the dominant molecular structure is the eight-membered ring and/or a chain with Se8 molecular fragments. The optical transmission spectrum was recorded at different temperatures in the range 77-300 K. The optical bandgap ET was calculated from the optical absorption coefficients α using Tauc law : αν=C(hν-Er)2, where hν is the photon energy. The temperature dependence of ET can be approximated by a linear relation : [MATH].
© EDP Sciences 1995