Study On Organic/Inorganic Phosphor Using For White-LED

White light-emitting diode has the characteristics of saving energy, environment protection and will become the main lighting production. Most commercial White-LED is in the manner of light conversion. The phosphors emit yellow light excited by the blue light and the two lights mix into white light. The phosphor has become one of the key techniques for fabricating White-LED. In this thesis, the synthesis and properties of organic-inorganic phosphor is studied.After analyzing the character of the phosphor and synthesizing method, it is found that the organic dye had the excellent luminous property of the organic luminescent molecule, but it has the disadvantage of the instability of the organic material for the heat, chemistry and mechanism. So it is necessary to seek one carrier of the organic. When the organic dyes were doped into silicon dioxide (SiO₂), it can be synthesized organic-inorganic composite luminescence material. It had both the excellent luminous property of the organic luminescent molecule and the stability of the inorganic material for the heat, chemistry and mechanism. So this kind of composite phosphor was considered as the ideal fluorescence materials. The organic-inorganic composite phosphor was synthesized with sol-gel method in this paper, which based on the raw material of TEOS and organic fluorescent dye. Some of the properties were researched, including the influence of the doping concentration of the organic fluorescent dyes, the ratio of H₂O to TEOS and the pH value on the reaction time and the material performance. Using the testing method of PL spectra, XRD, TEM and SEM, the properties of composite phosphor were identified, including spectrum, structure, granularity and appearance. It can be seen from the TEM that the powder is transparence in nanometer size. PL spectra indicates that the excitation wavelength is 450nm and the emission wavelength is 520nm, the excitation spectra peak is not changed with the doping concentration but the intensity of fluorescence is inflected by it, and the best doping concentration is 5 ×10^-4mol/L. The excitation band is wide so that it satisfies the requirement of the white-LED.