Investigation of structural, morphological, optical and dielectric properties of Ni2+ modified CdTe nanoparticles

CdTe nanoparticles doped with ${\text{Ni}}^{2+}$ ions were synthesized by microwave assisted method and found to be hexagonal crystalline structure with the favoured orientation. Using the Debye-Scherrer equation, the size of CdTe nanocrystallite with ${\text{Ni}}^{2+}$ ions was measured between 23.29 nm and 25.50 nm. Pure and doped CdTe nanoparticles have a direct band gap observed between 2.65 and 3.66 eV by UV–Visible spectroscopy. Pure and ${\text{Ni}}^{2+}$ doped CdTe have an ultraviolet and visible absorption band. Photoluminescence analysis reveals two strong emission peaks at 367 nm and 469 nm for both pure and Ni doped CdTe. The dielectric properties of CdTe nanoparticles were studied in the frequency range of 10Hz-10MHz at different doping levels of ${\text{Ni}}^{2+}$ ion. It is observed that dielectric constant along with dielectric loss decreases on increasing frequency. The refractive index and extinction coefficient of Ni doped CdTe NPs decrease as the Ni content increase.