Preparation Of Eu³⁺ Doped Yttrium Borates And WO₃Films By Electrodeposition And Their Photoelectrochemical Performance

Energy shortage and environmental pollution are the bottlenecks of social development and improvement of human life. The search of energy-saving devices and clean energy is the urgent demand now. The solar energy is a regenerative and clean energy. The rare-earth luminescent materials and semiconductor materials are the mian devices in using solar energy, and this interested researchers a lot. But the photoelectric properties of these materials often effected by the structure of buck and interface, so find a suitable method to study the relationship of structure and photoelectric properties has important scientific significance. Moreover it is the core of material device application to make thin film materials, so develop the easy way to product high performance films is the trend of further application. We used the borate with various structurals and WO3as reseach objects, used Eu3+as luminescent center and structure probe, we developed a easy, cost-saving methed-electrodeposition to achieaved Eu3+doped yttrium borate and WO3films, and their structure, morphology and photoelectric properties have been measured. The content of this thesis are listed as following:(1) Electrodeposition of YBO3:Eu3+and Y3BO6:Eu3+films at different voltage and their characterization:YBO3:Eu3+and Y3BO6:Eu3+films achived by simply adjusting applied potentials in aqueous solution containing B, Y and Eu ions. We characterized these films by IR, XRD, SEM and PL, and disscused the mechanism of formation and the luminensent effect of Eu3+doping. The photoluminescence (PL) properties of electrodeposited films show that the emission of the magnetic dipole transition (5D0â†'7F1) around610-630nm is stronger than that of the electron dipole transition (5D0â†'7F2) at590nm in Y3BO6:Eu3+films, which are consistent with the lower symmetry of Y3BO6crystal structure. The longest decay times from5D0â†'7F1emissions at590nm are2.24and3.78ms, for5mol%Eu3+doped YsBO6and1mol%Eu3+doped YBO3, respectively.(2) Preparation and characterization of Eu3+doped WO3films. The WO3films were first prepared by electrodeposition on ITO electrode and droped add certain content of Eu3+, then obtained WO3/Eu2(WO4)3films after calcinations. The crystal structal and morphology were changed measured by XRD, SEM and EDS before and after Eu3+doping. The photoluminescence (PL) showed that with the thickness of Eu2(WO4)3increasing, the light it emits stronger. Also we studied the photoelectrochemical properties of the films and found that the film with13nm Eu2(WO4)3has the best photoelectrochemical performance, its photocurrent density is6.5times larger than the WO3film, the IPCE and APCE are5.5and5.3times larger than WO3film, respectivily.