Non-volatile Optoelectronic Memory with “Self-Refined” N-Type Conjugated Polymer Floating Gate for Multistate Storage

Optoelectronic coupling programming successfully combines optoelectronic sensing, long-term storage, and multilevel storage functions, garnering increasing attention. In this work, upon introducing a self-refinement strategy to induce vertical phase segregation in a multicomponent system, a nonvolatile organic optoelectronic memory is proposed with one-step preparation. That is, an n-type conjugated polymer is dispersed into the p-type semiconductor@insulating polymer blend system, serving as a floating gate. The resulting film with a 5% semiconductor content is optically transparent. In the self-refinement process, the p-type semiconductor preferentially crystallizes at the top, and the n-type conjugated polymer is “retained” in the insulating matrix at the bottom, thus forming a charge transport layer and floating gate in one step. A light-assisted storage mechanism is identified. The prepared transistors exhibit stable bistability after 1 s of photoassisted programming/electrical erasure, with a memory ratio >10⁴ and a retention time of more than 10⁴ s. Such devices demonstrate multibit optoelectronic memory characteristics in ultraviolet and visible-light ranges. By changing the light intensity, pulse width, and electric pulse, the conductive states can be modulated linearly. Consequently, this device exhibits 16 states under multiple programming. Finally, the application of the multibit optoelectronic memory in color image recording is demonstrated.