Study of effects of Mn in CdS nanocrystals

Mn²⁺-doped CdS nanocrystals have been synthesized by adopting an aqueous solution precipitation method. These nanocrystals have been studied using X-ray diffraction (XRD), X-ray fluorescence (XRF), optical absorbance, photoluminescence (PL), DC electrical conductivity measurements and positron annihilation lifetime spectroscopy (PALS). The system has been found to be in the hexagonal phase. PL spectra have been studied on most prominent exciton peaks within the wavelength range (586–731 nm). The emission intensity is found to increase on increasing Mn²⁺ ion concentration (0–5%). Electrical conductivity lies within 0.819×10⁻⁶ to 1.69×10⁻⁶ Ω⁻¹ m⁻¹ and the system shows power law dependence for n=3–3.77. The Cd vacancies concentration has been found to decrease on increasing Mn%.