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.