Raman studies on Ag-ion doped CdZnS luminescent alloy quantum dots

• Published in: Chemical physics letters 2010-07, Vol.495 (1-3), p.63-68
• Main Authors: Sethi, Ruchi, Sharma, Prashant K., Pandey, A.C., Kumar, Lokendra
• Format: Article
• Language: English
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2010.06.016

Un-doped and Ag-ion doped CdZnS alloy nanocrystals were synthesized using methaacrylic acid (MAA) as a capping agent. A continuous higher frequency shift in optical phonon modes was observed in the Raman spectra of the samples with increasing Zn composition demonstrating a typical ‘one-mode’ type behavior of the alloy material. Furthermore, the influence of MAA concentration on the optical and vibrational properties was also investigated. Transmission electron micrograph (TEM) of the samples shows that the CdZnS nanocrystals were embedded in the matrix of MAA. In addition, tremendous attention was paid towards the power induced Raman shift in the alloy nanocrystals. [Display omitted] . ►In this report, for the first time, we have investigated the power induced Raman studies of CdZnS alloy quantum dots. The effect of excitation laser power is investigated to understand the variation in phonon line shape and position of the longitudinal optical phonon modes. ►We have adequately described the mechanism to show how the incorporation of various amount of Zn2+ can amend the vibrational property of CdZnS:Ag alloy nanocrystals. ►Effect of methaacrylic acid capping agent is also inspected on the structural, optical and vibrational properties of the Cd0.6Zn0.4S:Ag and the results were discussed in details. Un-doped and Ag-ion doped CdZnS alloy nanocrystals were synthesized using methaacrylic acid (MAA) as a capping agent. A continuous higher frequency shift in optical phonon modes was observed in the Raman spectra of the samples with increasing Zn composition demonstrating a typical ‘one-mode’ type behavior of the alloy material. Furthermore, the influence of MAA concentration on the optical and vibrational properties was also investigated. Transmission electron micrograph (TEM) of the samples shows that the CdZnS nanocrystals were embedded in the matrix of MAA. In addition, tremendous attention was paid towards the power induced Raman shift in the alloy nanocrystals.