Chromaticity Regulation Of Nano - Silicon Composite Fluorescent Materials

Fluorescent material is an important optical functional material having a wideapplication in flat panel displays, cathode ray tubes, solid state lighting, etc..Chromaticity coordinates is a quantitative means studied emission colors of thefluorescent materials. Nanometer porous silicon is a good room-temperaturefluorescent material, its chromaticity in CIE1931XYZ color space is red, which cannot be applied in full-color display industry. This paper aims to develop a convenientmethod to calculate the chromaticity coordinates of fluorescent materials, investigatechromaticity tunability of porous silicon based nanocomposite fluorescent materials,and provide the technical basis for the fabrication of full-color display devices.To study the chrominance tunability of porous silicon, we develop a pure spectralmethod calculating the chromaticity coordinates of the fluorescent material with thedefinition of the chromaticity coordinates. This method can obtain the reliablechromaticity values only using the fluorescence spectral data of the luminescentmaterial, without regard to physical appearance and reflectivity of the light emittingmaterial, is an effective technique for the rapid measurement of the chromaticitycoordinates of the fluorescent materials.Using the sponge-like porous silicon (PS) films as two-dimensional porousmatrixes, the alkaline sol-gel solutions of zinc acetate as the original materials of ZnOnanocrystals, we prepared ZnO/PS nanocomposite films by the sol-gel spin coatingtechnology, and investigated the effects of Zn2+concentration in sol-gels andannealing temperature on their chromaticity tunabilities. It is found that thechromaticity of the nanocomposites could be tuned from red to green-blue byincreasing the concentration of zinc cations in the sol-gels from4to260mM. A typical nematic liquid crystal5CB was employed in our experiment as the fillerto modify the fluorescent chromaticity of porous silicon. It is found that the originallyred chromaticity of porous silicon films in CIE1931XYZ color space canbe tuned to blue by simply adjusting the amount of liquid crystal molecules in themicrochannels of the porous films. With increasing the content of the liquid crystalmolecules in the microchannels of PS matrix, the chromaticity of5CB/PSnanocomposite films in CIE1931XYZ color space can be effectively regulated fromred to blue-violet region, and achieved white light emission. Our results havedemonstrated that the chromaticity of porous silicon films in CIE1931XYZ colorspace can be efficiently tuned by liquid crystal infiltration.This paper developed a simple, rapid pure spectroscopic methods calculatedchromaticity coordinates of fluorescent material, prepared ZnO/PS and5CB/PSnanocomposite films, effectively achieved the chromaticity tunability of thenanometer PS in the CIE1931XYZ chromaticity space, which provided key rawmaterials for the realization of the full-color display.