Thomas, Stuart and Adamopoulos, George and Anthopoulos, Thomas (2013) Be-doped ZnO thin-film transistors and circuits fabricated by spray pyrolysis in air. Journal of Display Technology, 9 (9). pp. 688-693. ISSN 1551-319X
Full text not available from this repository.Abstract
We report the fabrication of zinc oxide (ZnO) thin film transistors (TFTs) and simple integrated circuits by spray pyrolysis, and examine the role of beryllium (Be) as a dopant. Doping is achieved through addition of Be-acetylacetonate into the parent Zn-acetate precursor solution followed by film deposition through spray pyrolysis. The microstructural properties of as-grown Be-ZnO films with different dopant concentrations are investigated using a combination of atomic force microscopy and x-ray diffraction techniques, which show the formation of polycrystalline films. Introduction of Be is found to impact the degree of crystallinity of ZnO films where a dramatic decrease in the average grain size is observed with increasing Be concentration. To assess the effects of Be-doping on the electrical properties of ZnO films we have fabricated Be-ZnO based TFTs using different doping concentrations. The average electron mobility calculated from these transistors is on the order of ~2 cm2V-1s-1 with the threshold voltage (VTH) exhibiting a strong dependence on Be concentration. The ability to control Vth through the introduction of Be has been exploited for the fabrication of unipolar inverters with symmetric trip-voltages and good noise margins.