Electronic Properties of Amorphous SixGe1−x:H Films

Amorphous Si x Ge 1− x :H films are prepared by decomposition of SiH 4 /GeH 4 mixtures in a rf glow discharge. With increasing Ge‐content the optical gap as well as the energy and the half width of the luminescence peak decrease linearly. It is concluded that by admixture of Ge the tail state distribution becomes steeper and that the concentration of defects is considerably enhanced. Already small amounts of Ge lead to a drastic decrease of the photoconductivity (ημτ‐product).