Colloidal CdSe quantum dots (QDs) have attracted wide attention in recent years for use in a variety of applications including fluorescent tags for biological imaging, single-electron transistors, light emitting diodes, lasers, and solar cells.
In most articles, CdSe QDs have been synthesized at temperatures above 200 °C using trioctylphosphine oxide (TOPO) as solvent and trioctylphospine (TOP) as capping agent which are hazardous in nature. We have developed a much cheaper and green Non-TOPO/TOP-Based synthetic route of a series of CdSe QDs in the high boiling point solvents by injection of Se powder into a Cd oleic acid solution without use of TOP. N-hexadecane was selected as the solvent. It is cheaper, environmentally friendlier, and more stable in the atmosphere than the reported solvents such as TOPO or ODE. Herein a natural product oleic acid was used as the acid, which is much cheaper and environmentally friendlier than hexylphosphonic acid or tetradecylphosphonic acid.
The CdSe quantum dots have been successfully synthesized at various temperatures. The increase in particle size with red shift in colour was also confirmed by the UV–Vis absorption spectra. Ultraviolet and visible absorption spectra were recorded at room temperature. Photoluminescence spectra were measured and the photoluminescence quantum yield was obtained. X-ray powder diffraction analysis was employed. The X-ray diffraction pattern provided information about crystalline phase of the CdSe quantum dots as well as the average crystallite size. To further clarify the particle size of CdSe QDs we used transmission electron microscopy and dynamic light scattering.