The Preparation And Properties Of Ga₂O₃: Mn Electroluminescent Thin Films

With the developments of electronic information, military, aeronautic and aerospace technology, the more demands for the display which is the man-machine interface are need. Display technology will develop great in such aspects as full color, high luminescence, high contrast, flatting, low energy consumption, heath and environment protecting. AC(alternating current) inorganic thin-film electroluminescent (TFEL) display device, which has many merits such as full solid, active light-emissive, wide viewing, rapid responding and great environment adaptability, has been gaining much attention. Especially, AC oxide-based thin-film electroluminescent device, with great thermo-chemical stability, long life-span, good display performance, will gain great applications.In this dissertation, the deposition and heat-treatment technique of Ga₂O₃:Mn phosphor thin film used for TFEL device and its luminescent property have been studied. The phosphor thin film of Ga₂O₃:Mn was deposited by electron beam evaporation. By refractive index measuring and microstructure analysis such as surface morphology and crystal structure, the relations between the microstructure and luminescent property of Ga₂O₃:Mn thin film and the deposition and heat-treatment of Ga₂O₃:Mn thin film were studied, the art of deposition and heat-treatment optimized, the moderate parameter of the deposition and heat-treatment of Ga₂O₃:Mn thin film determined. Ga₂O₃:Mn thin film electroluminescent devices taking BaTiO3 ceramic as substrate, which has better luminescent property, were made.Research results show that heat-treatment temperature has important effect on crystal structure and orientation of the Ga₂O₃:Mn thin film. with the heat-treatment temperature increasing, the crystallization of Ga₂O₃:Mn thin film increase gradually, and its crystal structure charges from non-crystalline to polycrystalline, from mixed crystal structure composed of monoclinic, hexagonal and cubic crystal systems when the heat-treatment temperature is low to monoclinic structure, gradually. The color of the light emitting from Ga₂O₃:Mn TFEL device is green. The main peaks of the emitting spectrum lie mainly between 490nm and 535nm. With the increasing of driving voltages, the blue shift of spectral peaks is observed. The luminescence property of Ga₂O₃:Mn TFEL device, is not only related to the crystallization of Ga₂O₃:Mn thin film phosphor, but also depend mainly on its crystal structure and orientation.