Time-domain measurements of spin relaxation processes of dangling-bond defects in hydrogenated amorphous silicon

Spin relaxation processes of dangling-bond defects (g=2.055) in hydrogenated amorphous silicon (a-Si: H) and in deuterated amorphous silicon (a-Si: D) have been measured in the time domain by using the pulsed electron spin resonance technique. Phase relaxation measured as two-pulse echo decay is dominated by dipolar field fluctuations arising from hydrogen (or deuterium) nuclear spin flip flops. The inversion recovery curves of a-Si: H and a-Si: D are similar, which indicates that hydrogen hyperfine interactions are not directly involved in the spinlattice relaxation.