Ni-incorporated cadmium sulphide quantum dots for solar cell: An evolution to microstructural and linear-nonlinear optical properties

Cadmium sulphide (CdS) compounds have attracted interest due to their applications in opto-electronic devices such as solar cell, sensor, photodiode, etc. The performance of such devices are strongly depends on structure, morphology, and optical properties. Here we report, Ni-incorporated CdS quantum dots(QD) synthesized by conventional chemical co-precipitation method. Ni concentration (0, 2, 4, 6 and 8 wt-%) on Ni-incorporated CdS QD and its microstructural and linear-nonlinear optical properties are extensively investigated. Optical studies derived from UV-ViS. are performed to estimate linear-nonlinear parameters of Ni-incorporated CdS QD by utilizing the absorption and reflection spectra. The optical band gap values decrease from 2.53 to 2.33 eV as Ni content increases. On the other hand, the refractive index values increase with increasing Ni content. Additionally, skin depth, electrical-optical conductivity, and nonlinear parameters are effectively influenced by increasing Ni content in CdS QD.XRD studies confirm that the Ni-incorporated CdS QD exhibits a hexagonal crystal structure with a strong (002) preferential orientation. X-ray peak profile analysis by Scherer method and modified Williamson-Hall method is employed to calculate the crystallite size and lattice parameters such as strain, stress, and energy density of the Ni-incorporated CdS QD. The obtained results indicate that the crystallite size of QD estimated from Scherer and Williamson-Hall methods are correlated and in the range of 2.10-17.89 nm. Energy-dispersive X-ray spectroscopy(EDS) confirms the incorporation of Ni in CdS QD.

Automated summary

This paper reports on the synthesis of nickel-doped cadmium sulfide (CdS) quantum dots (QD) using a conventional chemical co-precipitation method. The effects of nickel concentration on the microstructure and linear-nonlinear optical properties of the Ni-incorporated CdS QD are extensively studied. The results show that the optical band gap decreases and the refractive index increases with increasing nickel content in the CdS QD. Additionally, the skin depth, electrical-optical conductivity, and nonlinear parameters of the CdS QD are also affected by the nickel content. XRD studies confirm a hexagonal crystal structure with a strong (002) preferential orientation for the Ni-incorporated CdS QD.