Electrodeposition Of Rare Earth Ions Doped α-KY₃F₁₀ Films And Their Luminescence Performance

Rare-earth ions doped luminescent materials have broad applications in fields of laser,3D display, biological label, and solar energy conversion owning to their abundant energy level transition, light conversion modes and long-life intense luminescence. Compared to oxides, rare earth-doped fluoride system with lower phonon energy, have been widely used as the most efficient up-conversion luminescent materials. Therefore, rare earth-doped fluoride luminescent materials have attracted lot attentions.Electrodeposition is known as a chemical solution method to grow thin films with mild conditions. Compared to other techniques, electrodeposition has capability of controlling of compositions and structures of films only by altering value of voltage or adding small amount of additives and also advantages of non-pollution, low-cost and. In this thesis, an anodic electrodeposition process has been developed to grow rare earth ions doped α-KY3F10 films from aqueous solution at 60℃. The structure, morphology and photoluminescence of the electrodeposited films were well characterized. The thesis includes two parts which are listed as follows:(1) α-KY3F10:Yb3+/Er3+ films have been obtained from aqueous solution by electrodeposition at 60℃ and their up-conversion emissions have been characterized. First, pure α-KYb3F10:Er3+(2 at.%) films were obtained by anodic oxidation method. XRD, SEM, FL, IR and others measurement were used to characterize the electrodeposited films. Compared with unannealed films, films annealed at 300℃ exhibited much better up-conversion performance. Moreover, because of the high contents of Yb in the films, the intensity ratio of red to green as high as 22.7 was obtained. The value is better than that of NaYF4：Er films prepared in the same condition. α-KYb3F10:Er3+films with different ratios of Y/Yb had different intensity ratio of red to green (from 22.7 to 1.47) were prepared by altering the ratio of Yb to Y in KY3F10 by anodic oxidation process.(2)α-KY3F10:Eu3+ films have been obtained by electrodeposition using above mentioned process excepted using Eu3+ ions as dopants instead of Er3+ ions. The low asymmetric structure of α-KY3F10 makes α-KY3F10:Eu3+films emit high purity of red emissions under the excitation of 394 nm laser.