Light-induced electron spin resonance in amorphous hydrogenated germanium

We report the observation of light-induced electron spin resonance (LESR) i n amorphous hydrogenated germanium. Two new lines with zero crossings near g=2.01 and g=2.03 were detected and ascribed to electrons and holes in the conduction- and valence-band-tail states, respectively. The ratio between t he LESR spin densities of both lines is approximately one, suggesting the a bsence of spin pairing, charge defect creation, or LESR of dangling bonds. The growth and decay spectra exhibit dispersive behavior with a dispersion parameter similar to 0.5. The decay spectrum is best fit assuming bimolecul ar recombination. The LESR spin density depends weakly on the photogenerati on rate as a sublinear power law. (C) 1999 American Institute of Physics. [ S0003-6951(99)03925-X].