Light-Assisted/Light-Driven Memory Behaviors with Small Molecule- Fluoropolymer-Small Molecule-Stacked Floating-Gate Heterostructures

A photo memory is a device capable of modulating the state of the memory by light without a separate photodetector. As a result, as two functions can be performed with a single device, the photo memory enables the miniaturization of the image detection system and can be free from the signal delay issue that occurs between different devices through the reduction of the metal routing length. Along this line, we demonstrate an organic photo-memory transistor (PMT) with a small-molecule fluoropolymer-small-molecule-stacked floating-gate heterostructure. The proposed PMT consists of N,N '-ditridecyl-3,4,9,10-perylene tetracarboxylic diimide, which has photoresponsive properties to visible light as a floating-gate and 2,7-dioctyl [1]benzothieno[3,2-b] [1]benzothiophene as a channel layer. The proposed PMT device can be erased under light illumination and exhibits a large memory window of approximately 32 V, and the read current (IRead) shows stable retention characteristics in the programmed and erased states. The erasing operation can be performed under four different wavelengths of light, and multi-level storage is formed according to the light intensity. Furthermore, the PMT device operates the memory only with light without bias because of the photovoltaic effect. Text image mapping depends on whether or not the device is illuminated.