Study on Vacancy Related Defects of CdS Nanoparticles by Heat Treatment
In this Work a Method of Incorporating Anion or Cation Vacancy during Synthesis Stage of CdS Nanoparticles to Induce Defect Level Emission Is Presented. Further the Influence of Temperature on this Vacancy Related Defects Is Also Studied. the as-Prepared Samples with Co-Precipitation Technique Were Heat Treated with Different Time Intervals at a Constant Temperature of 200 °C. From UV-Visible Absorption Spectra, the Band Gap of both the as-Prepared and Heat Treated Samples Are Calculated to Be 3.51 Ev Indicating that there Are No Significant Changes in the Size of Nanoparticles. The Photoluminescence Spectra of both Samples Showed Emission Bands Corresponding to Band Edge and Defect Levels. Further from the Spectra, it Was Observed that the Intensity of Band Edge Luminescence Decreases with Increase of Heat Treatment Duration. This Is due to the Fact that Induced Defects Have Reached the Surface of Nanoparticles.
N.S. Roshima et al., "Study on Vacancy Related Defects of CdS Nanoparticles by Heat Treatment", Journal of Nano Research, Vols. 18-19, pp. 53-61, 2012