Low-Voltage Transparent Indium–Zinc–Oxide Coplanar Homojunction TFTs Self-Assembled on Inorganic Proton Conductors.

\H3\PO4-incorporated nanocolumnar \SiO2-based proton conductors show an enhanced electric double layer (EDL) capacitance value of \sim\!\!\8 \ \mu \F/cm^2 at 20 Hz. The upper frequency limit of EDL formation is found to be higher than 10 kHz. Transparent indium–zinc–oxide (IZO) coplanar homojunction thin-film transistors gated by such proton conductors are fabricated by one metal shadow mask self-assembled method. The operating voltage is found to be as low as 0.6 V. The current on/off ratio, the subthreshold swing, and field-effect mobility are estimated to be \6 \times \10^5, 68 mV/dec, and 12 \cm^2/\V\cdot \s, respectively. Such transparent transistors hold promise for low-cost and portable electrochromic devices and invisible biochemical sensors. [ABSTRACT FROM PUBLISHER]