Transport and recombination in amorphous p-i-n-type solar cells studied by electrically detected magnetic resonance

A detailed study of electrically detected magnetic resonance in p-i-n-type solar cells made from amorphous silicon is reported. It is found that the spectra depend sensitively on the applied voltage, and the intensity and photon energy of the light. The results support the present understanding of the mechanism of the device. It is shown that in general, the transport in the dark, and the charge collection under illumination, are controlled by recombination in the bulk of the i layer. Only when a high forward bias is applied and under illumination does recombination at the p-i interface play an important role. Degradation by both current and illumination results predominantly in an enhancement of the recombination rate in the i layer.