Household alternating current electricity plug-and-play quantum-dot light-emitting diodes.

As an intrinsically direct current device, quantum-dot LED cannot be directly driven by household alternating current electricity. Thus, a driver circuit is required, which increases the complexity and cost. Here, by using a transparent and conductive indium-zinc-oxide as an intermediate electrode, we develop a tandem quantum-dot LED that can be operated at both negative and positive alternating current cycles with an external quantum efficiency of 20.09% and 21.15%, respectively. Furthermore, by connecting multiple tandem devices in series, the panel can be directly driven by household alternating current electricity without the need for complicated back-end circuits. Under 220 V/50 Hz driving, the red plug-and-play panel demonstrates a power efficiency of 15.70 lm W and a tunable brightness of up to 25,834 cd m. The developed plug-and-play quantum-dot LED panel could enable the production of cost-effective, compact, efficient, and stable solid-state light sources that can be directly powered by household alternating current electricity.