Highly Efficient Perovskite/Organic Hybrid White Electroluminescent Devices with Extended Operational Lifetime and Wide Color Gamut.

Abstract

Rapid and substantial progress is made in monochromatic perovskite light-emitting diodes (LEDs), however, challenges remain in achieving white electroluminescence for high-definition display and lighting applications with perovskites as emitters. Here, a proof-of-the-concept configuration is proposed that successfully demonstrates monolithic perovskite/organic hybrid white LEDs (P/O-WLEDs) with a wide color gamut for the first time. In this configuration, pure-green and deep-blue organic emission units are successively superimposed onto a red emission perovskite layer, forming a hybrid emissive system. The unique carrier transporting and luminescent characteristics of the organic emission units facilitate a broadened carrier distribution, high exciton utilization, and narrowband emission peaks. Consequently, the developed P/O-WLEDs achieve a peak external quantum efficiency of 21.1%, ultralow turn-on voltage of 2.6 V, and simultaneously a significantly extended operational lifetime of 21.9 h (LT50 at an initial luminance of 500 cd m^-2). Furthermore, by regulating the charge transport properties through an RbI-treated perovskite unit and an optimized thin LiF layer, the P/O-WLEDs not only maintain comparable performance but also demonstrate obviously improved spectral stability and a suitable correlated color temperature, opening a new avenue for the development of display and lighting technologies.