Enhancement of the photoelectric properties of composite oxide TiO2-SrTiO3 thin films

Enhancement of photoelectric properties related to surface chemistry states of composite oxide TiO2-SrTiO3 has attracted extensive interest over the past few years owing to its unique internal structure. In this paper, the composite oxide TiO2-SrTiO3 thin films have been successfully fabricated via sol-gel method. Various characterizations such as X-ray diffraction, field emission scanning electron microscope, and X-ray photo electron spectroscopy are utilized to investigate the crystal phase, surface morphology, and chemical compositions of the composite oxide TiO2-SrTiO3 thin film. By measuring the photoluminescence spectrum, we investigate the band gap and the electron transition. It is found that PL result is closely related to the information of charge carrier trapping. Current-voltage characteristics indicate that the TiO2-SrTiO3 has better photoelectric performance than that of pure strontium titanate and rutile titanium dioxide. Additionally, the composite oxide TiO2-SrTiO3 thin film shows favorable photoelectric response, high sensitivity, and good stabilization. First-principle calculation based upon the density functional theory (DFT) is the first time to explicate the energy band and state density of the composite oxide of the TiO2-SrTiO3 with the appropriate model. This study deepens understanding of the photoelectric properties and electron structure of the new composite oxide TiO2-SrTiO3 thin film, which is expected for further applications in optoelectronic devices.

Automated summary

This study successfully fabricated TiO2-SrTiO3 composite oxide thin films via sol-gel method and investigated their crystal phase, surface morphology, and chemical compositions through various characterizations. The results show that the composite oxide exhibits enhanced photoelectric properties, with the photoluminescence spectrum closely related to charge carrier trapping information. Additionally, first-principle calculations based on DFT provided insights into the energy band and state density of the composite oxide, deepening understanding of its photoelectric properties and electron structure for potential optoelectronic device applications.