A brief review on device operations and working mechanisms of organic transistor photomemories

Abstract

A memory cell based on a three-terminal device or so-called transistor has greatly drawn attention for decades owing to its superior memory behavior and more versatile electrical property modulation compared to conventional two-terminal device. Recent progress shows that by introducing a photoactive charge storage interlayer in between dielectric and active semiconducting channels, the electrical properties of such a device can be feasibly controlled with photons, rendering novel ultrafast photo-recovery or photo-writing non-volatile transistor memories. Numerous photoactive materials, diverse structures and micro-to-nano scale dimensions of the charge trapping layer, including the plausible physical mechanisms, have been investigated and proposed to significantly level up the memory behaviors. As a result, the transistor photomemory has been emerging in many potential applications. In this review, different photoactive materials for the charge trapping layer will be presented briefly yet comprehensively. The device framework and its working principles will be systematically discussed and distinguished according to their unique memory behavior and applications. We also introduce a new insight into the tunneling effect in assisting photo-assisted memory transistors as a new branch and research venue. Lastly, the potential applications benefitted from transistor photomemory are exemplified to further understand the organic transistor photomemory devices comprehensively.