The Preparation And Properties Study Of Dy³⁺Doped LaVO₄Thin Films

The luminescent thin films have very good optical properties. They have been extensively investigated due to their potential applications in cathode ray tubes, flat panel display devices, field emission displays, communications devices, luminescent solar concentrators and so on. Dy3+doped LaV04thin films have good luminous intensity, high transmittance in the UV and visible region, so when it is applied in the solar cell, the life and efficiency of the cell can be greatly improved.In this article, we make a system study of the Dy3+doped LaVO4thin films. The structure and optical properties are studied from the fourier transform infrared (FTIR) spectra and the emission spectra, as well as the luminous mechanism is explained. The experimental results obtained from the Dy3+doped LaVO4thin films have a certain significance to the study and application space of the luminescent thin filmsThe whole thesis consists of six parts and the main contents of each part are as follows.In chapter one, we make a simple introduction of the application background and the study progress home and abroad of the luminescent thin films. We especially introduce the application of the luminescent thin films in solar cell, at the same time, the topic selection basis and the main research work are also introduced.In chapter two, the technique and principle of sol-gel method preparing thin films are introduced, as well as the experimental condition and progress of sol-gel method preparing LaVO4:Dy3+thin films are introduced in detail. In addition, the characterization methods of LaVO4:Dy3+thin films are summarized and at the same time the laboratory apparatus used in the experiment and their principles are also listed in this chapter. At last we list qualification and reference test conditions of all the laboratory apparatus.In chapter three, the effect of ratio of citric acid to metal ions in the precursor solution on the morphology and optical properties of LaVO4:Dy3+thin films is studied. We find that this ratio did not has any influence on the transmission spectra of the films, but it has an important influence on the emission intensity of all the films and when the ratio is2:1, the film prepared from such precursor has the highest emission intensity and the most uniform surface.In chapter four, the effect of the precursor solution concentration added with PVA and PEG respectively on the morphology and optical properties of LaVO4:Dy3+thin films is studied. The transparent and uniform film was obtained when PVA was added into the precursor solution with the concentration of the solution being0.2mol/L. When PEG was added, with increasing the solution concentration, the transmission spectra do not change greatly, the grain spacing decrease, the films become compact, as well as the luminous intensity is enhanced.In chapter five, the influence of PEG concentration with the same precursor concentration on the morphology and optical properties of LaVO4:Dy3+thin films is studied. With increasing the PEG concentration, the surface of the films become more and more compact and the emission intensity become stronger and stronger. But with further increasing the PEG concentration, the surface become incompact and the emission decrease slightly. When the PEG concentration is0.12g/ml, the film has the best morphology and the highest emission intensity.Finally, a brief summery as well as the prospect of the future work is given in chapter six.