High mobility nanocrystalline silicon transistors on clear plastic substrates

We demonstrate nanocrystalline silicon (nc-Si) top-gate thin-film transistors (TFTs) on optically clear, flexible plastic foil substrates. The silicon layers were deposited by plasma-enhanced chemical vapor deposition at a substrate temperature of 150/spl deg/C. The n-channel nc-Si TFTs have saturation electron mobilities of 18 cm²V/sup -1/s/sup -1/ and transconductances of 0.22 μSμm/sup -1/. With a channel width to length ratio of 2, these TFTs deliver up to 0.1 mA to bottom emitting electrophosphorescent organic light-emitting devices (OLEDs) which were fabricated on a separate glass substrate. These results suggest that high-current, small-area OLED driver TFTs can be made by a low-temperature process, compatible with flexible clear plastic substrates.