Strategies to Enhance Light Emission from Two-Dimensional Perovskite Light-Emitting Diodes: Challenges and Future Opportunities

Two-dimensional (2D) metal halide perovskites have paved a technological renaissance in light-emitting diode (LED) technology. These 2D perovskites possess tunable photophysical properties, including higher exciton binding energies, multiple quantum well structures, natural cascaded energy funneling, and band gap versatility, which render them an outstanding candidate for future LED development. However, there are still some challenges that exist in the field for developing perovskite-based commercial display devices, which include phase impurity in 2D perovskites, their inefficient energy funneling, the high density of surface defect states, and imbalance charge injection. Numerous efforts such as phase engineering, surface passivation, and interface modulation have been demonstrated to address these challenges and to improve light emission from these perovskite-based LEDs (PeLEDs). Here, we provide a detailed analysis of existing challenges in PeLEDs from a fundamental perspective and discuss different strategies adopted to address these challenges. Finally, we discuss a detailed roadmap for the development of future high-performance commercial PeLEDs.