Luminescence Of Rare Earth Doped Gallium Oxide Based Semiconductor

As an important wide-bandgap semiconductor,gallium oxide has high thermal stability and excellent chemical and physical properties.On the other hand,rare earth ions themselves are good luminescent materials,and the effective combination of oxide semiconductors and rare earth ions has always been the focus of attention.Since the ion radius of the rare earth ion and the host cation are different,it is not easy for the rare earth ion to be incorporated into the semiconductor in the form of replacing the lattice position.In response to these problems,the author carried out research on the luminescence of rare earth-doped gallium oxide-based semiconductors.The first chapter reports the current research status and market applications of rare earths,as well as the electronic structure properties and photoelectric properties ofβ-Ga₂O₃.In Chapter 2,it is reported that the plane wave pseudopotential method based on density functional theory（DFT）calculates the structure of Ce-doped Ga₂O₃ with different concentrations.The calculation results show that the band gap is slightly reduced afterβ-Ga₂O₃ is doped with rare earth Ce.small.Through binding energy analysis,it is known that Ce atoms preferentially replace Ga2 positions.In the band gap,due to the influence of the rare earth element 4f layer electrons,a new energy level appears.The higher the doping concentration,the wider the impurity energy level.The third chapter reports the preparation of rare earth Ce-doped gallium oxide nanomaterials by chemical vapor deposition,which was successfully prepared on a silicon substrate.Under the condition of controlling the process variables,a control experiment was carried out,and the morphology,structure and composition of the sample were tested using different other characterization methods analysis.The conclusion is that the low concentration of rare earth Ce doping has little effect on the crystal structure of gallium oxide.The crystal structure of the sample is monoclinic,similar toβ-Ga₂O₃,and the growth law of surface morphology has been studied.And summary.Chapter 4 reports the electronic structure and optical properties of the Eu-dopedβ-Ga₂O₃ structure by doping with different concentrations of Eu,as well as the Eu-doped gallium oxide occupying two different positions.The calculated results show that the doping of Eu improves the optical properties ofβ-Ga₂O₃.In the deep ultraviolet region,the refractive index increases significantly,and the optical transition intensity in the low-energy region also increases significantly.This calculation provides a theoretical basis for gallium oxide doped rare earth related experiments.Chapter 5 reports the preparation of rare earth Eu-doped gallium oxide phosphor powder by hydrothermal method,and the successful preparation of luminescent materials.In the photoluminescence spectrum,there is an obvious luminescence peak at 620 nm.In the case of controlled variables,control experiments with different concentrations and different annealing temperatures have been done.The experimental results found that the luminescence intensity increases with the increase of doping concentration,and the crystallinity and luminescence intensity are the best when the annealing temperature reaches800°C.Finally,a co-doping experiment of rare-earth Ce and rare-earth Eu is done,and it still has luminescence characteristics,and a new luminescence peak is found,which has good application prospects.