Photoluminescence spectra of CdSe/ZnS quantum dots in solution

• Fluorescence spectra of quantum dots core and core shell in organic solvents.
• Solvents influence on photoluminescence spectra of quantum dots.
• The longer wavelength is due to the core of the quantum dots.
• The shorter wavelength is due to the interaction between the solvent and the shell (ZnS) in excited state.

The spectral properties of CdSe/ZnS core–shell quantum dots (QDs) of 3 nm size have been studied under different organic solvents, concentrations and temperatures. Our results showed that the absorption spectra of CdSe/ZnS in benzene have two humps; one around 420 nm and another at 525 nm, with a steady increase in absorption along UV region, and the absorption spectral profile under a wide range of concentrations did not change. On the other hand, the photoluminescence (PL) spectra of CdSe/ZnS in benzene showed two bands one around 375 nm and the other around 550 nm. It could be seen that the band at 375 nm is due to the interaction between the shell (ZnS) with the solvent species in high excited state, and the band at 550 nm is due to core alone (CdSe).

Figure optionsDownload as PowerPoint slide