Studies On Preparation And Characterization Of Nanophosphors And Their Luminescent Properties

The lack of low cost low-pressure phosphors with excellent performance is one of the key factors, which restrict the commercialization of FED. The main purpose of this work is to prepare low-pressure phosphors used for FED in order to accelerate the speed of commercialization of the FED.The effects of temperatures of vacuum evaporation and calcination on the morphology and luminescent properties of the commercial phosphor No.2 and No.1 were investigated by SEM, TEM, XRD, and Emission Spectrum measurements. For the commercial phosphor No.2, the results show that the particle sizes increase, the luminescent intensity is enhanced firstly and then depressed with the increase of the evaporation temperature, the exciting voltage is 1200V. The distribution of the particles is improved, the crystallization degree is raised, the luminescent properties are enhanced with the increase of the calcination temperature from 800℃to 1200℃after evaporated at 200℃in vacuum the exciting voltage is 1500V, and the majority of the particle sizes are between 5 nm and 85 nm. But the distribution become bad, the luminescent properties are enhanced firstly and then depressed, the crystallization degree are also raised with the increase of the calcination temperature from 800℃to 1200℃, if the samples are first evaporated at 300℃in vacuum. For the commercial phosphor No.1, the results show that the particle sizes decrease first and then increase, the distribution are improved first and then depressed, the luminescent intensity is enhanced first and then decreased with the increase of the evaporation temperature (the exciting voltage is 1200V); however, it losts the luminescent property after calcined at 1200℃.ZnGa 2 O4 Phosphors were prepared by chemical method and solid-state mill method, respectively. SEM and TEM were used to characterize the phosphors. The measurements show that the distributions are different if the raw materials are milled in different way. The particle sizes and morphology of the phosphors are different, which prepared by chemical method, if the molar ratio of ZnO:Ga₂O₃ is changed.Phosphor coats were coated by scrape method, and their luminescent properties were characterized qualitatively. The measurements show that the commercial phosphor No.2 is red light emitting, the commercial phosphor No.1 is green light emitting, ZnGa₂O₄ Phosphors are green and blue light emitting, respectively, corresponding to the chemical and solid-state mill preparation method.