Functionalized films are provided comprising a film of ZnO or ZnO alloy disposed over a supporting substrate and a layer of organic molecules comprising terminal carboxylic acid linkage groups, wherein the organic molecules are bound to a surface of the film of ZnO or ZnO alloy via the terminal carboxylic acid linkage groups. Thin film transistors comprising the functionalized films are also provided. The functionalized films may be formed using polycrystalline ZnO and saturated fatty acids, such as stearic acid.