Transparent organic thin-film transistors and nonvolatile memory devices fabricated on flexible plastic substrates

Transparent and flexible organic thin-film transistors (OTFTs) and nonvolatile memory devices were developed. The memory device is based on OTFTs by incorporating self-assembled gold nanoparticles in the organic dielectric layers as the charge storage elements. The organic memory devices exhibited good programmable memory properties with respect to the program/erase operations, resulting in controllable and reliable threshold voltage shifts by hole trapping/detrapping in the gold nanoparticles. The organic memory devices could be electrically programmed and erased, leading to a large memory window of around 15 V. Additionally, the long term data retention (>10(5) s) and the stable cyclic bending tests (>2000 cycles) confirmed that the flexible memory devices exhibited good electrical reliability as well as mechanical stability. The organic memory devices were composed of a solution-processed organic dielectric layer/metallic nanoparticles and a low-temperature processed organic semiconductor layer. Additionally, transparent indium-tin oxide (ITO) deposited at room temperature was used for the gate and source-drain electrodes to fabricate transparent memory devices. Therefore, this approach could potentially be applied to advanced transparent and flexible electronic devices as well as integrated organic device circuits.