Temperature-dependent recombination dynamics and electroluminescence characteristics of colloidal CdSe/ZnS core/shell quantum dots

Exploring the temperature-dependent electroluminescence (EL) properties of quantum dots (QDs) is not only critical for the fundamental understanding of charge recombination processes in quantum dot light-emitting diodes (QLEDs) but also important to expand their particular applications at cryogenic temperatures. Herein, the temperature-dependent EL properties of typical CdSe/ZnS core/shell QDs were systematically studied for both the standard and inverted QLEDs in the temperature range of 100-300 K. It was found that EL intensity and efficiency were gradually enhanced and exhibited a pronounced blue shifting in EL spectra with the decrease in temperature. We demonstrated that temperature-dependent EL behaviors mainly originated from the inherent properties of QDs, while the different device structures could induce some fine temperature-dependent behaviors on this basis. Moreover, the effective Joule heat dissipation at low temperatures protects the charge transport and QD layers from thermal decomposition and damage, which prolongs the operational lifetime of devices.

Automated summary

The temperature-dependent electroluminescence properties of quantum dots (QDs) were systematically studied, showing enhanced EL intensity and efficiency with a blue shift in spectra at lower temperatures. The behaviors mainly originated from the inherent properties of QDs, with different device structures inducing minor temperature-dependent effects. Effective Joule heat dissipation at low temperatures helps protect charge transport and QD layers, prolonging device lifetime.