Controlled Synthesis GaP Nanocrystalline And GaP/morin Nanocomposites Research

GaP nanocrystalline is a kind of important III-V compound semiconductor nanomaterials, because of their different from body materials, especially the novel optical properties and electrical properties, so that it attractive widespread interest in the scientific research and technical application. Several techniques have been developed to fabricate various GaP nanostructures, including metal-organic decomposition precursors, metal-organic chemical vapor deposition, hydrothermal synthesis. However, these route requires high temperature and long reaction duration, which usually results in the aggregation of GaP nanocrystalline, the decrease of surface reactivities, hard to get the high quality nanocrystalline. In this paper, based on our previous work, according to the recent progress of nanomaterials preparation methods and the mechanism of crystal growth, using a reverse micelle method and multi-steps solvothermal method tries to the full control of the preparation of GaP nanocrystalline, in order to get high quality materials. After many tests, we get some fairly good results, and discusses on these results, lay the foundation for the next step for nano-material preparation.In dimethyl benzene solution to add CTAB form reversed micelle, which become main place of reaction in dimethyl benzene. Reversed micelle is spherical, the resulting particles is spherical particle, the size of particle is small, CTAB coated weakened the reunion, was sussessfully used in the preparation of GaP nanocrystalline with high monodispersity. After many tests to changes the quality of nanocrystalline by the multi-steps solvothermal synthesis method, we got three times feeding, the best time and best addition amount. First charging is growth nucleation, and the second is the third things improve crystallinity, make narrow particle size distribution. Finally we got small and narrow particle size distribution, single good dispersion, high crystallinity GaP quantum dots. The blue-shifted UV-vis absorption spectra are clear evidence of quantum confinement in these nanoparticles.Preparation GaP/morin nanocomposites by ultrasonic treatment.Two substances originally absorption is very weak, but the UV-vis absorption peaks of the composite are between that of GaP QDs and morin, and the intensities of the absorption peaks is much stronger, this can explain that the-OH groups of morin that can form strong complex bonds with surface atoms of GaP nanoerystals. In addition, we test the photoluminescence characteristics of GaP QDs and GaP/morin nanocomposites. When GaP QDs were dispersed into water shows very weak photoluminescence. But, the GaP QDs capped with morin would show very strong photoluminescence. The PL spectra of GaP QDs/morin nanocomposites with different ratio of 100:4.5,and the fluorescence quantum yield is 25% measure by Coumarin 307 as standard substance. Furthermore, the GaP/morin nanocomposites are rather stable.