OPTICALLY DETECTED MAGNETIC-RESONANCE (ODMR) IN A-SI-H

We report here on a systematic study of the influence of temperature T (4-70K) and defect density N(D) on the ODMR-spectra. In general the ODMR-spectra of undoped a-Si:H consist of three resonances, a quenching line Q and two enhancing lines E(s) and E(b). In all samples the broad and narrow E-lines are observed simultaneously and depend in a similar way on T and N(D). These E-lines are assigned to the recombination of exchange coupled e-h-pairs. It is shown that the broad signal can arise from the superposition of resonances of e-h-pairs with intrapair separations of 40-60 angstrom.