Controllable synthesis of CdSe/ZnS core–shell quantum dots by one-step thermal injection and application in light-emitting diodes

Abstract

Quantum dots (QDs) attract extensive attention because of their excellent optoelectronic performance. However, few research has been done on the synthesis of core–shell QDs by one-step thermal injection. Here the CdSe/ZnS core–shell QDs were successfully synthesized by a one-step thermal injection method. The synthesis process of CdSe/ZnS core–shell QDs was investigated from two aspects of reaction time and oleic acid dosage. The results suggest that the reaction time and the dosage of oleic acid have important effects on the optical properties of CdSe/ZnS core–shell QDs. The action mechanism of oleic acid was also explained in this paper. Moreover, highly efficient green quantum dot light-emitting diodes (QLEDs) were fabricated with CdSe/ZnS core–shell QDs on ITO glass substrate by rotary coating method. The minimum starting voltage of 1.91 V and the maximum brightness of 12,057 cd m−2 were achieved in the QLEDs. This study is of great significance for the development of the synthesis of core–shell QDs by one-step thermal injection and QLEDs.