Designing high-performance pure-red metal halide perovskite materials and light-emitting diodes for Rec. 2020 display

With the increasing demand of higher-quality display for Metaverse, pure-red metal halide perovskite lightemitting diodes (PeLEDs), as a fundamental optoelectronic element for achieving full-color displays, is highly desirable to satisfy the color standards of Rec. 2020 specification. However, the EQE performance and color purity requirement remain much room for improvement, and the operational stability is still an enormous challenge hindering them toward commercialization. In this review, the recent strategies toward efficient purered PeLEDs involving colloidal NCs, quasi-2D, 3D mixed-halide and lead-free materials have been summarized in detail. Meanwhile, the device architecture optimizations focusing on charge balance, interfacial engineering and light outcoupling are also highlighted. In addition, the operational stability challenge and improvement strategies for pure-red PeLEDs are discussed. Finally, an outlook is proposed regarding the future development for high-performance pure-red PeLEDs.