Study of the CuS/CdSe Quantum Dots on the Optical Properties of Green Synthesis

Chalcogenides based nanomaterials, such as CdSe are emerging as an important material offering transformative potential across multiple domains, such as photocatalysis, optoelectronics, sensing, and photo luminesce. In this study we synthesised CuS/CdSe quantum dots by varying CuS concentration through plant mediated green method. The copper sulfide synthesized at varying concentrations of the Se source, exhibited bonding configuration that are comparable to those of the Cd source. The goal of this igniting interest in these CdSe based composites, is by highlighting their numerous advantages across diverse applications. The FTIR spectra of these systems, exhibit a prominent vibrational peak at 732 cm-1 and a strong vibrational stretching band at 512 cm-1 belongs to N-H banding vibration. FTIR spectra in the higher-energy region, reveals an absorption peak, which can be attributed to the O-H stretching. The absorption spectra obtained through UV-visible absorption spectroscopy were recorded in the range of 200-800 nm. Using the Tauc formula, the band gap was calculated and it is 3.52 eV for pure CuS quantum dots and 2.93 eV for CuS/CdSe quantum dots, the method for regulating the light emission wavelength, attributed to the anticipated blue shift in absorption spectra. It is observed that the recorded photoluminescence emission spectra are in the absorption band edge state. The CS2 showed an emission peak at 378 nm, indicating a blue shift, as a result of the interaction between carriers and phonons. The improved photoluminescence properties of these systems will make them suitable for optoelectronics applications.