Tailoring the 2D/3D Phase Segregation for Highly Efficient Si-Based Perovskite Light-Emitting Diodes

Si-based perovskite light-emitting diodes (PeLEDs) show immense potential in optoelectronic device fields by combining the advantages of a mature silicon platform with the impressive light-emitting properties of halide perovskites. However, their external quantum efficiencies (EQEs) have lagged far behind those of their conventional glass-based counterparts. Herein, the microcavity effect is employed to enhance the light extraction ratio of Si-based top-emission PeLEDs by fine-tuning the thicknesses of the functional layers. Meanwhile, the methylammonium chloride (MACl) additive is used to regulate the crystallization process and promote 2D/3D phase segregation in perovskite layer, endowing the film with a significantly improved photoluminescence quantum yield (PLQY) due to both the desired energy funneling from the 2D phase to the 3D phase and the trap passivation brought by the 2D phase. Owing to these synergistic strategies, the optimal devices exhibit a record EQE over 20% and an intense radiant exitance up to 155.9 mW cm–2 and thus represent the best performing Si-based PeLEDs ever reported to our knowledge.