Flexible and Printed Organic Nonvolatile Memory Transistor with Bilayer Polymer Dielectrics

Abstract In this study, printed organic nonvolatile memory thin‐film transistors (TFTs) with phase‐separated tunneling layer is presented. Finely patterned electrodes are fabricated by reverse‐offset printing with 15 μm line width and 10 μm channel length. Memory devices are configured in a bottom‐gate bottom‐contact TFT structure with a high‐k gate blocking insulator poly(vinylidene fluoride‐co‐trifluoroethylene). A blended ink, which consisted of a small‐molecule p‐type organic semiconductor dithieno[2,3‐d;2′,3′‐d′]benzo[1,2‐b;4,5‐b′]dithiophene and a polystyrene dielectric, is fabricated using air‐pulse nozzle printing. The tunneling layer is formed during the active layer printing process with the blended ink by phase separation of small‐molecule and polymer. The printed memory TFTs with the phase‐separated tunneling layer exhibit significantly improved V_TH shifts (≈3 times), programmed/erased current ratio (>10³ A A⁻¹), switching speed (<100 ms), and estimated data retention (>10 years). This memory device can be applied to wearable electronics, smart Internet‐of‐Things devices, and neuromorphic computing devices.