Study of C6+ (80Â MeV) ion induced effects on CdS:Mn system

Manganese-doped CdS nanocrystals have been synthesized by using aqueous solution precipitation method. These samples of CdS:Mn have been subjected to irradiation using C6+ (80 MeV) under fluence of 1 × 1013 ions/cm2. For characterization X-ray diffraction (XRD), optical absorption, photoluminescence (PL), surface morphology and positron annihilation spectroscopy (PALS) have been performed. The system has been found in hexagonal phase having crystalline size distribution of 18-20 nm. The PL intensity has been found to be decreased, while optical band gap has been found to be increased of irradiated samples. Positron lifetime component τ1 (210-183 ps) is due to annihilation from diffused vacancies on the grain surfaces and τ2 (399-367 ps) is due to positrons directly trapped in the vacancy cluster like defects. The third component τ3 (2453-2064 ps) is due to annihilation of orthopositronium, at interfaces and boundaries within the nanocrystals.