Influence of pH on the thermo-optic properties of CdSe QDs prepared by a microwave irradiation method

In this letter the optical behavior as well as the thermal properties of CdSe quantum dots (QDs) capped with mercapto succinic acid (MSA) are studied and analyzed. CdSe QDs with an average particle size of 7.0 nm are prepared by a microwave irradiation method. The unique structure of MSA plays an important role in determining the PL intensity and better stability by controlling the pH of the medium. A significant increase in thermal diffusivity with pH values is observed with a mode matched thermal lens method. At the optimum value of pH, the surface charge of nanoparticles increases, which increases the repulsive forces. The resulting reduced agglomeration of QDs enhances mobility and improves heat transport. There is a clear correlation between luminous intensity and thermal diffusivity in these nano fluids containing CdSe QDs.