CURRENT-INDUCED DEGRADATION IN BORON-DOPED HYDROGENATED AMORPHOUS-SILICON - A NOVEL INVESTIGATION TECHNIQUE

A novel technique for controllable degradation and monitoring of a boron-doped layer as used in thin film solar cells is presented. The thin p-type layer under investigation is grown embedded in a n-i-n structure. Upon biasing the structure, excess electrons are injected into the layer giving rise to a degradation process. Complete recovery after annealing indicates the metastable nature of the process. The degree of degradation can be monitored by following changes of the forward current flowing into the structure. A simple model enables the interpretation of the experimental curves in terms of doping activation and increased density of defects in the doped layer. © 1995 American Institute of Physics.