Structural and optical response of 2-Mercaptoethonal capped CdS nanocrystals to Fe3+ions

Cadmium sulfide (CdS) semiconductor nanocrystals (NCs) doped with Fe3+ have been synthesized via a solution-based method utilizing dopant concentrations of (05%) and employing 2-mercaptoehonal as a capping agent. X-ray diffraction (XRD) results showed that the undoped CdS NCs are in mixed phase of cubic and hexagonal, where as the doped CdS NCs are in hexagonal phase. The crystallite size was increased from similar to 1.2 nm to similar to 2 nm. Diffuse reflectance spectroscopy studies (DRS) reveals that the band gap energy was decreased with Fe doping and it lies in the range of 2.58 - 2.88 eV. Photoluminescence (PL) spectra of undoped CdS NCs show a strong green emission peak centered at 530 nm and a weak red emission shoulder positioned at 580 nm. After doping all the luminescence intensity was highly quenched and the green emission peak was shifted to orange region (580 nm), but the position of weak red emission shoulder was unaltered with doping. FTIR studies revealed that the NCs were sterically stabilized by 2-mercaptoethanol. (C) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)