Optically addressed read–write device based on tandem heterostructure

Abstract An optically addressed read–write sensor based on two stacked p–i–n heterojunctions is analyzed. The device is a two terminal image sensing structure. The charge packets are injected optically into the p–i–n writer and confined at the illuminated regions changing locally the electrical field profile across the p–i–n reader. An optical scanner is used for charge readout. The role of the sensor configuration and readout parameters on the image acquisition process is analyzed. The presence of a metallic light-screening layer between the writer and the reader proved to be effective to optically decouple the two p–i–n structures, while maintaining good electrical conductivity. The optical-to-electrical transfer characteristics show high quantum efficiency, broad spectral response, and reciprocity between light and image signal. A numerical simulation supports the imaging process.