Preparation and optical property of Co2+: CdS nanocrystals

Co doping CdS nanocrystals were synthesized in aqueous solution using mercaptoacetic acid as stabilizer. The prepared nanocrystals were examined using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) and UV-vis absorption spectroscopy (ABS). The cubic zinc blende nanocrystals were determined and the sizes were estimated by XRD. The compositions of the nanocrystals was confirmed by XPS, the resultes indiacated that Co²⁺ existed in the as-prepared nanocrystal. FTIR indicated that the doped as well as undoped nanocrystals were capped by mercaptoacetic acid molecules. Ultraviolet-visible absorption spectra indicated that Co²⁺ is located at the surface of the nanocrystals.