Synthesis of Co-Doped CdS Nanocrystals by Direct Thermolysis of Cadmium and Cobalt Thiolate Clusters

Abstract

Co-doped CdS (Co:CdS) nanocrystals with controllable morphology (quantum dots and nanorods) were easily synthesized by direct thermolysis of (Me4N)2[Co4(SC6H5)10] and (Me4N)4[S4Cd10(SPh)16] under different precursor concentration, in virtue of the ions exchange of molecular clusters. The Co:CdS quantum dots were produced under low precursor concentration, and the Co:CdS nanorods could be obtained under higher precursor concentration. The Co-doping effect on the structure, growth process, and property of CdS nanocrystals was also investigated. The results indicated that the Co-doping was favorable for the formation of the nanorod structures for a short reaction time. In addition, the Co-doping in the CdS lattice resulted in the ferromagnetic property of the Co:CdS quantum dots at room temperature. Moreover, compared with the CdS quantum dots, the Co:CdS quantum dots exhibited obvious quantum confinement effect and photoluminescence emission with slightly red-shift.