Structural, morphological and optical properties of CdSe(S) quantum dots

Semiconductor nanomaterials are tiny light emitting particles and have stimulated great interest among researchers might be due to their applications in solar energy conversion, optoelectronic devices, molecular and cellular imaging and ultrasensitive detection. The present study reports a facile and low-cost synthesis strategy of CdSe(S) nanoparticles via chemical co-precipitation method by controlling the experimental protocols. FTIR spectral study confirms the presence of CdSe(S) nanoparticles. XRD spectra suggest for their polycrystalline nature and prominent peak corresponding to cubic structure of CdSe(S) quantum dots. Besides this, some peaks corresponding to other structures, such as hexagonal, are also present. The crystallite sizes of grown CdSe(S) quantum dots were found to be 3 nm, 5 nm and 6 nm, respectively. The particle size obtained by TEM analysis was also in the range of 3nm to 8nm which agrees well with those reported by the XRD data. Low value of energy band gap shows their polycrystalline nature. Moreover, the as prepared CdSe(S) were found to exhibit quantum confinement effect, which leads to spatial enclosure of electronic charge carriers within the nanocrystals.