Flexible TFTs based on solution-processed ZnO nanoparticles

Abstract

Flexible electronic devices which are lightweight, thin and bendable have attractedincreasing attention in recent years. In particular, solution processes have been spotlightedin the field of flexible electronics, since they provide the opportunity to fabricate flexibleelectronics using low-temperature processes at low-cost with high throughput. However,there are few reports which describe the characteristics of electronic devices on flexiblesubstrates. In this study, we fabricated flexible thin-film transistors (TFTs) on plasticsubstrates with channel layers formed by the spin-coating of ZnO nanoparticles andinvestigated their electrical properties in the flat and bent states. To the best ofour knowledge, this study is the first attempt to fabricate fully functional ZnOTFTs on flexible substrates through the solution process. The ZnO TFTs showedn-channel device characteristics and operated in enhancement mode. In the flatstate, a representative ZnO TFT presented a very low field-effect mobility of1.2 × 10−5 cm2 V−1 s−1, while itson/off ratio wasas high as 1.5 × 103. When the TFT was in the bent state, some of the device parameters changed. Thechanges of the device parameters and the possible reasons for these changes will bedescribed. The recovery characteristics of the TFTs after being subjected to cyclic bendingwill be discussed as well.