Kinetics of the metastable optically induced ESR in<i>a</i>-Si:H

Abstract

The kinetics of a metastable, optically induced increase in the ESR in a-Si:H have been examined between 77 and \ensuremath{\sim}500 K. Isothermal annealing (decay) and inducing (growth) curves indicate that the decay is bimolecular and thermally activated with an activation energy of \ensuremath{\sim}1 eV, and the growth is relatively temperature independent. These kinetics are more easily explained through the optical rearrangement of charge in existing dimagnetic (negative-U) defects and less easily in terms of the optical creation of additional, paramagnetic localized states in the gap.