Nanosecond-Pulsed Perovskite Light-Emitting Diodes at High Current Density

Adv Mater. 2021 Nov;33(44):e2104867. doi: 10.1002/adma.202104867. Epub 2021 Sep 3.

Abstract

While metal-halide perovskite light-emitting diodes (PeLEDs) hold the potential for a new generation of display and lighting technology, their slow operation speed and response time limit their application scope. Here, high-speed PeLEDs driven by nanosecond electrical pulses with a rise time of 1.2 ns are reported with a maximum radiance of approximately 480 kW sr-1 m-2 at 8.3 kA cm-2 , and an external quantum efficiency (EQE) of 1% at approximately 10 kA cm-2 , through improved device configuration designs and material considerations. Enabled by the fast operation of PeLEDs, the temporal response provides access to transient charge carrier dynamics under electrical excitation, revealing several new electroluminescence quenching pathways. Finally, integrated distributed feedback (DFB) gratings are explored, which facilitate more directional light emission with a maximum radiance of approximately 1200 kW sr-1 m-2 at 8.5 kA cm-2 , a more than two-fold enhancement to forward radiation output.

Keywords: high-speed operation of PeLEDs; metal-halide perovskites; perovskite light-emitting devices; pulsed operation; transient charge carrier dynamics.