Nanowire-Based High Speed Transparent and Flexible Thin-Film Transistor Devices

High-performance transparent and flexible thin film transistors (TFTs) were fabricated on glass and plastic substrates using alligned SnO₂ nanowires as the channel material. High densities of crystalline SnO₂ nanowires were dry-transferred directly onto the glass/plastic substrates, followed by low-temperature patterning of the source/drain and gate electrodes. Transparent TFTs fabricated on glass substrates show excellent electrical properties and optical transmittance. Excellent mechanical flexibility can be further obtained under cyclic tension experiments in devices fabricated on plastic substrates. The charge carrier mobility was estimated to be as high as 160 cm²/V·s — two orders of magnitude higher than that of conventional amorphous-silicon or organic TFTs. Cutoff frequency > 70 MHz and on/off ratio > 10⁶ have also been demonstrated. The low-cost nanowire growth and dry-transfer processes make this approach a cost-effective means to fabricate transparent and/or flexible TFTs on non-conventional substrates.