STORAGE DEVICE HAVING A SEMICONDUCTOR TARGET

An information storage device having an evacuated envelope containing writing means which is adapted to produce, in response to an input signal and by causing emission of secondary electrons, a charge pattern on a storage target disposed within the envelope. The storage target includes a semiconducting layer and a storage layer providing alternate semiconducting regions and storage regions. The semiconducting layer consists essentially of semiconductor material of substantially single conductivity type and the storage regions consist essentially of a secondary electron-emissive insulating compound of a semiconductor material. One of the two layers is interrupted and exposes portions of the other layer. A collector electrode disposed within the envelope intercepts the secondary electrons emitted by the target. The target is provided with means for applying electrical potential thereto and extracting signals therefrom.