Time-domain measurements of the dangling bond spin-lattice relaxation in hydrogenated amorphous silicon-germanium alloys

The dangling bond spin relaxation times in a-Si:Ge:H alloys are determined with pulse electron spin resonance techniques as a function of alloy composition and temperature. Over a wide alloy range two spin lattice relaxation components are detected in saturation recovery measurements. The two components are attributed to Si- and Ge- dangling bond states. It is found that the respective relaxation times, which in the pure alloys are different by two orders of magnitude due to the difference in the spin orbit coupling of Si and Ge, both gradually change with alloy composition but maintain largely different values also in the alloys. As a function of temperature the relaxation times decrease as T--m (m approximate to 2). Copyright (C) 1996 Published by Elsevier Science Ltd