Photosensitive thin film materials and devices

Planarization of photosensitive device technology promises to expand the application options for this type of material. In this paper, we report on the production of highly photosensitive thin films, without the use of post-deposition processing, which promise compatibility and integrability with III-V and Si processing. We investigate the optical bleaching of structural defects, responsible for the photosensitive response exhibited by our materials, and assess defect thermal stability. It is seen that films deposited at a substrate temperature of 600°C demonstrate defect stability up to temperatures of approximately 550°C, whereas films deposited on ambient temperature substrates show evidence of structural relaxation at temperatures above 250°C. Such relaxation in the ambient temperature samples is accompanied by changes in the photosensitive response of the material. Finally, we demonstrate the operation of waveguide-based integrated photonic devices within our films.