Amorphous semiconductors for switching, memory, and imaging applications

Performance and reliability of amorphous semiconductor devices that deal with the handling of information in the form of switching, modulation, storage, and display are discussed. Structural changes between a disordered and a more ordered state and the concomitant large change in many material properties offer the possibility of using amorphous semiconductors for high-density information storage and high-resolution display devices. The structural changes can be initiated by various forms of energy such as an electrical pulse, a short light pulse, or a brief light exposure. Many materials show good structural reversibility. The sensitivity of an amorphous photostructural film is amplified by several orders of magnitude by first forming a latent image by photonucleation and subsequent dry development by heat or radiation. Examples of optical contrast and resolution in image formation are given. The major differences between crystalline and amorphous semiconductors are briefly outlined.