Quantum‐Dot Light‐Emitting Diodes for Outdoor Displays with High Stability at High Brightness

Quantum dot light-emitting diodes (QLEDs) are considered to be the candidate light sources with the most potential for applications in displays. Recent advances in luminance, external quantum efficiency (EQE), and even the operation lifetime of QLEDs have already satisfied the requirements for low-light-level displays. However, the short operation lifetime under high brightness limits the application of QLEDs for outdoor displays and lightings. Here, demonstrated are green QLEDs with a T-95 operation lifetime reaching up to 2500 h at high brightness (1000 cd m(-2)) with a high peak EQE of 23.9%, current efficiency of 100.5 cd A(-1), and low efficiency roll-off at high current. Both the EQE and lifetime of the QLEDs are superior to those reported to date for all solution-processed green QLEDs. These major advances are qualitatively attributed to the use of a shell-tailoring strategy for producing compositional graded CdZnSe/ZnSe/ZnSeS/ZnS quantum dots with a high photoluminescence quantum yield, suppressed nonradiative Forster resonant energy transfer and Auger recombination, and favorable valence band alignment for enhanced hole injection. Collectively, this work represents a huge step forward in eventually realizing QLEDs for high-brightness display and lighting applications.