J. Phys. Colloques
Volume 42, Numéro C4, Octobre 1981Proceedings of the Ninth International Conference on Amorphous and Liquid Semiconductors
|Page(s)||C4-819 - C4-822|
J. Phys. Colloques 42 (1981) C4-819-C4-822
DARK- AND PHOTOCONDUCTIVITY OF COMPENSATED a-Si : HB. Hoheisel, R. Fischer and J. Stuke
Fachbereich Physik, Universität Marburg, D-3550 Marburg, F.R.G.
In Li-diffused B-doped a-Si : H the dark conductivity can be changed from n- to p-type by annealing. Going from n- to p-type conduction, the photoconductivity changes by a factor of about 102 with a minimum close to compensation. The recombination kinetics is of second order in the n- and p-type range, and of first order around compensation. We conclude that the recombination lifetime is determined by charged centers near midgap which alter their charge state with the position of the Fermi level. As the p- and n-photoconductivities have different activation energies, the two kinds can be observed together when EF is near midgap : the photoconduction is n-type at low temperature and p-type at high temperature.