Modelling of drift mobility experiments on a-Si:H

The authors present recent results of a study of the behavior of electronic carriers in a-Si:H, using the model of multiple trapping (MT) in an exponential density of states. in previous publications, using Monte Carlo simulations, they showed that the standard low field MT model gives reasonable agreement with experiment particularly if the Meyer-Neldel effect is included in the model. They report here on the results of including two other effects. First, they have included a simple model of field assisted detrapping, to take account of the effect of high fields. They obtain very good agreement with the results of measurements on both electrons and holes, from a number of laboratories. In addition, they show here that the validity of an effective temperature approach can be checked easily by comparison with experiment. Second, they have presented a simple model of rapid relaxation of trapped carriers. This model offers the possibility of removing the apparent inconsistency between these measurements, and other experiments.