Efficient light-emitting diodes based on oriented perovskite nanoplatelets

Solution-processed planar perovskite light-emitting diodes (LEDs) promise high-performance and cost-effective electroluminescent devices ideal for large-area display and lighting applications. Exploiting emission layers with high ratios of horizontal transition dipole moments (TDMs) is expected to boost the photon outcoupling of planar LEDs. However, LEDs based on anisotropic perovskite nanoemitters remain to be inefficient (external quantum efficiency, EQE <5%) due to the difficulties of simultaneously controlling the orientations of TDMs, achieving high photoluminescence quantum yields (PLQYs) and realizing charge balance in the films of assembled nano-structures. Here, we demonstrate efficient electroluminescence from an in situ grown perovskite film composed of a monolayer of face-on oriented nanoplatelets. The ratio of horizontal TDMs of the perovskite nanoplatelet film is similar to 84%, which leads to a light-outcoupling efficiency of similar to 31%, substantially higher than that of isotropic emitters (similar to 23%). In consequence, LEDs with a peak EQE of 23.6% are achieved, representing highly efficient planar perovskite LEDs.

Automated summary

Solution-processed planar perovskite light-emitting diodes (LEDs) offer high performance and cost-effective electroluminescent devices suitable for large-area display and lighting applications. LEDs utilizing perovskite nanoplatelets with a high ratio of horizontal transition dipole moments (TDMs) have demonstrated an enhanced light-outcoupling efficiency and achieved a peak EQE of 23.6%, making them highly efficient planar perovskite LEDs.