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

Abstract

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 (>10⁵ 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.