Detoxifying quantum dot LEDs

Quantum dot light-emitting diodes (QD-LEDs) are attractive for large-panel displays because of their efficiency, colour purity, reliability and cost-effective fabrication. The best-performing devices contain cadmium, however, which presents toxicity and environmental issues. Efforts have therefore turned to more benign alternatives, such as InP, but the performance of devices based on these materials is still far behind that of their cadmium-containing counterparts. Eunjoo Jang and colleagues now demonstrate an approach for engineering InP/ZnSe/ZnS QD-LEDs to achieve external quantum efficiencies close to the theoretical maximum, with high brightness and extremely long lifetimes, representing a performance comparable to state-of-the-art cadmium-containing QD-LEDs. This study suggests that InP-based QD-LEDs could be used in commercial displays in the near future.