Enhanced UV emission of TiO₂–ZnO nanocomposite films synthesized by simplified sol–gel dip-coating method

TiO₂–ZnO composite film was regarded as a promising candidate for UV emitter devices. For exploring a lower cost and convenient preparation method for highly efficient UV-emission TiO₂–ZnO composite film, we used a simplified method in which mixing ZnO sol and TiO₂ sol directly to prepare TiO₂–ZnO nanocomposite films with a varied atomic ratio of Zn/(Ti+Zn) (TiO₂, Z20, Z40, Z60, Z80, ZnO) on glass substrates and discussed its optical properties for the first time in this study. The photoluminescence (PL) spectra indicated that the UV emission of the composite films was greatly enhanced compared with that showed by single-phase TiO₂ or ZnO film. In particular, the UV emission intensity of Z60 composite film was enhanced by a factor of 10 compared to that of single-phase ZnO or TiO₂. The enhanced PL intensity of the composite films could be attributed to fluorescence resonance energy transfer (FRET).