J. Phys. Colloques
Volume 42, Numéro C4, Octobre 1981Proceedings of the Ninth International Conference on Amorphous and Liquid Semiconductors
|Page(s)||C4-143 - C4-146|
J. Phys. Colloques 42 (1981) C4-143-C4-146
MAGNETIC FIELD DEPENDENCE OF THE PHOTO- AND DARK CONDUCTIVITY IN DOPED a-Si:H FILMSD. Weller, H. Mell, L. Schweitzer and J. Stuke
Fachbereich Physik, Universität Marburg, F. R. G.
We have studied the influence of magnetic field on the photo-conductivity σph and dark conductivity σd of glow discharge deposited a-Si:H films doped with phosphorus or boron up to a nominal content of 7 %. The relative change of σph is of the order of 10-4 to 10-2 depending on temperature and on the dopant concentration. Its dependence on magnetic field strength B varies significantly with the position of the Fermi level. In highly doped material (B2H6/SiH4 > 10-3 and PH3/SiH4 > 10-2), we observe - for the first time in this material - magnetic field induced changes of σd. This magnetoconductivity effect is attributed to a second current path in localized band tail states close to the Fermi level.