A sensitive MNMOS structure for optical storage

A sensitive device structure for the storage of optical signals is presented. It is based on an indium tin oxide - silicon nitride - aluminum - silicon dioxide - silicon (MNMOS) combination. The light signal is transformed to electric charge through optical excitation of charge carriers in the two metal layers. The charge is transported in the nitride conduction and valence bands to the aluminum. The latter layer is confined between the two insulator layers, thus forming a potential well for the storage of the optically induced charges. Light exposure times down to 0.1 ms are enough to store readable data by a light power of 90 ¿W/cm² at 2.2 eV photon energy.