Improved thin film transistor performance of solution-processed-zinc-oxide nanorods with spin-on-glass capping layer

Due to the vulnerability of various organic and oxide materials to the atmosphere, a protective layer is often used to improve device performance and stability. In this study, we use a spin-on-glass (SOG) layer to encapsulate a solution-processed-zinc-oxide (ZnO) film. ZnO loses oxygen very easily to the atmosphere and even loses Zn at relatively low temperatures. An SOG capping layer prevents the loss of oxygen without degrading its crystalline properties. We demonstrate the properties of a bottom-gate transistor with a capping layer; it shows improved electrical properties with a mobility of 0.5 cm2/V.s. and stability. Physical characterization reveals that the defect density with a capping layer is much lower than it is without it. A capping layer can also prevent the loss of oxygen at the annealing temperature of 350 °C.

► Improved electrical performance of ZnO nano-particle for TFT device.
► SOG capping layer protects the ZnO active layer and cause better stability.
► SEM and XRD analysis was performed to confirm particle size and crystallinity, respectively.
► Photo luminescence spectroscopy has been performed to evaluate the defect properties.
► Capping layer reduce the defect density and improve the semiconducting properties.