Recent Advances in Organic Phototransistors: Nonvolatile Memory, Artificial Synapses, and Photodetectors

Recent research interest in organic field-effect transistor (FET) memory has shifted to the functionality of photoprogramming in terms of its potential uses in multibit data storage and light-assisted encryption and its low-energy consumption and broad response to various optical bands. Phototransistor memory can be modulated through both electrical stress and light illumination, allowing it to function as an orthogonal operation method without mutual interference. Herein, the basic design concepts, requirements, and architectures of phototransistor memory are introduced. Design architectures such as channel-only, channel-with-photogate, photochromatic channel devices and floating gate, photoactive polymer, and organic molecule-based electrets are systematically categorized. The operational mechanism and impact of effective combinations of channels and electrets are reviewed to provide a fundamental understanding of photoprogramming as well as its potential future developmental applications as nonvolatile memory. Furthermore, recent advances in phototransistors and their diverse applications, including nonvolatile memory, artificial synapses, and photodetectors, are summarized. Finally, the outlook for the future development of phototransistors is briefly discussed. A comprehensive picture of the recent progress in phototransistors is provided.