Highly stable amorphous-silicon thin-film transistors on clear plastic

Hydrogenated amorphous-silicon $(a\text{-}\mathrm{Si}:\mathrm{H})$ thin-film transistors (TFTs) have been fabricated on clear plastic with highly stable threshold voltages. When operated at a gate field of $2.5\times {10}^5\mathrm{V}∕\mathrm{cm}$ , the threshold voltage shift extrapolated to only $\sim 1.2\mathrm{V}$ after ten years. This stability is achieved by a high deposition temperature for the gate silicon nitride insulator which reduces charge trapping and high hydrogen dilution during $a\text{-}\mathrm{Si}:\mathrm{H}$ growth to reduce defect creation in $a\text{-}\mathrm{Si}:\mathrm{H}$ . This gate field of $2.5\times {10}^5\mathrm{V}∕\mathrm{cm}$ is sufficient to drive phosphorescent organic light emitting diodes (OLEDs) at a brightness of $1000\mathrm{Cd}∕{\mathrm{m}}^2$ . The half-life of the TFT current is over ten years, slightly longer than the luminescence half-life of high quality green OLEDs.