Flexible and Transparent WO₃ Transistor with Electrical and Optical Modulation

Abstract

Flexible and transparent electrochromic transistors based on WO3 with dual and simultaneous optical and electrical modulation are presented. Devices provide more than 70% of optical transmittance modulation and more than six orders of magnitude of current variation by changing the gate potential only 4 V.

Reusable Cellulose‐Based Hydrogel Sticker Film Applied as Gate Dielectric in Paper Electrolyte‐Gated Transistors

“…Owing to the parasitic capacitance effect, spikes are observed during dynamic switching, which are more evident for faster switching frequencies . A significant variation of I DS between Off and On states up to three orders of magnitude is observed on a very short time scale for the lowest frequency (1 Hz), and the response times were determined around t on = 85 ms and t off = 3 ms. As already reported in some works, the value calculated for t on is largely superior than t off , as a result of the longer time required for electrochemical charging than discharging. The fast polarization response is a demonstration of the large concentration and mobility of ionic species in the electrolyte.…”

“…The fast switching speed verified by the developed flexible CHE‐gated transistor on paper is substantially superior when compared with other reported solid polymer electrolytes used for electrolyte gating, since they suffer from slow polarization response, limiting transistor's switching frequency to less than 1 Hz . The flexible and low‐cost devices reported here are not limited to low operation speed application and fits the requirements needed for circuit applications .…”

“…The former parameter is here determined considering the frequency at which the I on/off becomes equal to 10 (one order of magnitude), whereas the latter is defined as the time required to reach from 10% to 90% of the maximum current. These times will be addressed as off ( t off ) and on ( t on ) times, respectively . Ten consecutive cycles of gate voltage pulses were performed, providing information about the transistor's stability during dynamic switching.…”

“…The incorporation of oxide semiconductors in EGTs appears to be a promising and an emerging research field, since these materials show great potential to improve carrier mobilities, switching speeds, and chemical stability . In particular, oxide semiconductors with an amorphous microstructure offer advantage on low‐temperature processing and the ability to produce films with highly smooth surfaces that eradicate grain boundaries effects, which have unfavorable effects on the mobility of the devices .…”

Hydrogenation Dynamics of Electrically Controlled Metal–Insulator Transition in Proton‐Gated Transparent and Flexible WO3 Transistors

“…An interesting laboratory‐scale approach to realize electron or hole doping is to fabricate an ionic liquid or gel‐gated transistor, which is viewed as an alternative to chemical doping and has led to numerous intriguing phenomena and various applications . Preeminent examples include metal–insulator transition (MIT), induction and enhancement of superconductivity, structural phase transition, magnetic transformation, electrochromism, artificial synapses, and so on. However, the doping mechanism is acutely disputable.…”