Low-Temperature Solution Growth of High-Quality ZnO Thin Films and Solvent-Dependent Film Texture

Engineering of ZnO film texture with controlled crystal orientation has been realized by employing a solvent effect via a facile solution growth method. By increasing the ethanol content in aqueous/ethanolic solution, the crystal orientation is tuned from perpendicular to almost parallel to the substrate surface. ZnO film texture is further engineered by a secondary growth in the solution. A secondary growth of oriented nanorod arrays in the 50% ethanol solution leads to the coalescence of discrete nanorods throughout the whole film surface and transformation of discrete nanorod arrays into dense film. The dense ZnO films obtained exhibit a strong sharp UV luminescence and a weak broad green-yellow emission, demonstrating high-quality ZnO films can be grown by a low-temperature solution-phase approach.