Time-Controlled Photoluminescence and Electroluminescence of CdSe/ZnS Nanocrystals

摘要

We successfully synthesize CdSe/ZnS core/shell green quantum dots with different reaction times as light-emitting layer (LEL) of quantum-dot light-emitting diodes (QLEDs). Both the absorption peaks and photoluminescence peaks show obvious red-shift with increasing size with the increase of reaction times from 1 min to 10 min, which is attributed to the quantum confinement effect. Transmission electron microscope (TEM) and high resolution transmission electron microscope (HRTEM) images reveal that the CdSe/ZnS QDs are spherical, compact and dense in structure with a maximum particles size of ～8 nm. The highest luminance of 46505 cd m~(-2) and current efficiency of 11.2 cd A~(-1) are obtained with the reaction time of 6 min. These results suggest that the QLED performance and the characteristics of QDs can be tuned by the reaction time of QDs.