Field-effect transistors with thin ZnO as active layer for gas sensor applications

Zinc oxide based field-effect devices prepared for gas sensing applications are studied. For this purpose, bottom-gate transistors were fabricated using Pd as source and drain interdigitated electrodes with gate lengths varying from 0.3 to 2 μm. Thin (50 nm) zinc oxide films were grown with the aid of pulsed laser deposition (PLD) at room temperature and served as active and sensing layer. AFM and XRD analysis demonstrated the polycrystalline nature of the c-axis oriented ZnO films with nanoscale grain size (20–40 nm) with relatively high average roughness. Electrical and gas sensing measurements from the above-mentioned devices are presented.