The Investigation Of The Fabrication Of Porous Alumina And The Characteristic Of The Related Materials

The research focuses on the fabrication of the porous alumina and the photoluminescence investigation of the CdSe quantum dots. Anodic alumina templates have been obtained in the phosphorus acid and oxalic acid solution. The experiments have demonstrated that a highly ordered array can be obtained by re-anodizing technique. The relation between current and time showed the forming process of porous alumina template. The relation between the interpore distance and the anodic voltage is almost linear. The pictures of Scanning Electronic Microscopy showed that periodic pore arrangements were observed in some local positions of the template. Statistical results indicated that the porosity was only 8%, which is less than value 10%. Therefore, the pictures were consistent with the statistical results. The results show that the experiment conditions should be improved in order to fabricate the 10% porosity and periodic pore arrangements. CdSe quantum dots with different radii were obtained by the choice of reaction time. The photoluminescence properties of CdSe quantum dots with different radii are studied. The FWHM of photoluminescence of different quantum dots are nearly the same, which reveals that the nucleation centers are formed only at the beginning of chemical reaction and the size fluctuation does not increase with the increase of the reaction time. Thermal treatment and light illumination will reduce the photoluminescence efficiency and make a blue shift remarkably, especially in the condition of 110℃ and 150℃ thermal process. The electronic states were investigated by a model of the spherical square well with infinite depth and the radii of the quantum dots were estimated from the parameters of luminescence data. The photoluminescence investigation of CdSe quantum dots in porous alumina is presented. CdSe quantum dots in alcohol solution are implanted in porous alumina template. The results indicate photoluminescence efficiency only reduces by 10% after a month. Compared with CdSe quantum dots on aluminum substrate whose photoluminescence efficiency reduces by 40%, photoluminescence efficiency of CdSe quantum dots in porous alumina is better.