Abstract
We fabricated a bottom-gate thin film transistor (TFT) with the active layer of Indium-Gallium-Zinc Oxide (IGZO) nano particles prepared from water solution. The poly-crystallized InGaZn2O5 films were formed by spin-coating method and post-baked at low temperature (95 °C). The morphology of the IGZO film indicates that not only are the grain size and shape uniform but the cross section of the film appears dense, considering the films were fabricated by a solution process at low temperature. The TFT device shows good switching ability, high drain current (>105) and low threshold voltage (0.9 V). Its field-effect mobility of 2.3 cm2/V-s and current on-off ratio over 106 are very promising for TFT applications.We also investigated the zinc oxide (ZnO) and IGZO thin films subjected to laser irradiation. Structural, optical and electrical properties of the as-deposited and laser irradiated films at different laser energies were studied. The crystallinity of the structure increased and it became conductive after laser treatment. The transmittances without/with laser irradiation had a net rise of 85 % to 92 % and 80 % to 95 % (@550nm) for 250 nm ZnO and IGZO films, respectively. The quantity of IGZO enhanced transmittance was higher than that of ZnO. We fabricated thin film transistors (TFTs) with ZnO and IGZO as the active layer. The as- deposited ZnO/IGZO TFT devices had a field effect mobility of 0.19 cm2/V-s and 1.3 cm2/V-s, respectively. The electrical characteristics increased by more than 2.8 times for ZnO and by 5 times for IGZO of un-irradiated laser treatment. The field-effect mobility of ZnO and IGZO are 0.5 cm2/V-s and 7.65 cm2/V-s