Zinc Oxide Sheet Field-Effect Transistors
Résumé
The present work investigates charge carrier transport in back-gated field-effect transistors based on ZnO sheets (BG ZS-FETs). The ZSs used in this work have been synthesized via the catalytic-assisted vapor-liquid-solid process inside a horizontal quartz tube furnace at around 950 °C. The BG ZS-FETs were constructed as bottom-gate top-contact structures using suspended and non-suspended ZS as the active channel material. Assessment of key device performance metrics revealed excellent n-channel behavior with low off-state current in the femtoamp range, high on-state current (∼2 μA/μm), high on-to-off current ratio (>107), a steep sub-threshold swing of around 190 mV/dec, and field-effect carrier mobility of around 60 cm2/Vs. Temperature dependent charge transport studies reveal excessive mobility degradation in the non-suspended device while the same parameter in the suspended case appeared fairly stable. The present work is envisaged to benefit ongoing research towards the development of high performance ZS-based thin-film transistors.