2020 Volume 18 Pages 12-17
Direct Ga-doping into ZnO nanoparticles (NPs) were tried by thermal treatment mixed with Ga2O3 particles. Residual Ga2O3 particles were completely removed by appropriate centrifugation process. To confirm the Ga-doping, variations of sheet resistances for sprayed NP-layers on glass substrates were investigated, showing successful and dramatic reduction from GΩ sq−1-order to sub-kΩ sq−1. The minimum sheet resistance reached to 225 Ωsq−1. From X-ray diffraction and X-ray photoelectron spectroscopy analyses, it can be concluded that Ga atoms diffused from Ga2O3 into ZnO-NPs in the thermal treatment process, and some of them substituted for Zn atoms and were activated as donors. These results can contribute to continuous advance of ZnO-NP-based thin-film-transistor fabrication technique.