Carrier separation effects in hydrogenated amorphous silicon photoconductors with multilayer structures

Photogenerated electrons and holes can be separated efficiently by the built-in field present in hydrogenated amorphous silicon (a-Si:H) photoconductors with multilayer (ML) structures. Because of the carrier separation, the recombination rate of photogenerated carrier's decreases and this can lead to high photosensitivity and small photoinduced changes in a-Si:H ML photoconductors. We have observed that such carrier separation effects indeed occur in a-Si:H p-i-p type ML photoconductors. Some comments are made on the origin of the photoinduced changes in a-Si:H from the experimental results obtained for the p-i-p type photoconductors.