[TuP3G] Oxide Materials & Devices

[TuP3G-11] Influence of Wrinkle Structures in Sol–Gel-derived ZnO Thin Films on Optoelectronic Synaptic Behaviors

〇Seyeon Tak¹, SeungMin Song¹, JungBeen Cho¹, JunHyeong Park¹, Sung-Nam Lee¹ (1. Tech Univ. of Korea (Korea))

Zinc oxide (ZnO) is widely used in optoelectronic devices due to its wide bandgap and high electrical and chemical stability. In sol–gel-derived ZnO thin films, the soft-bake process strongly influences surface morphology and defect formation. This study investigates the effect of soft-bake temperature on nanoscale wrinkle structures and optoelectronic synaptic behavior in two-terminal ZnO devices. ZnO thin films were spin-coated on sapphire substrates, soft-baked at 110–190 °C, and annealed at 800 °C. Atomic force microscopy revealed pronounced wrinkle structures at 150 °C. Optical and electrical measurements showed enhanced photoluminescence, photocurrent, and persistent photoconductivity at 150–170 °C, indicating defect-assisted carrier trapping. These results demonstrate that controlling soft-bake temperature effectively modulates ZnO surface structure and defect states, leading to improved synaptic memory characteristics.