PEAI‐Assisted Defect Passivation for Efficient Silicon‐Based Perovskite Light‐Emitting Devices

Abstract Near‐infrared perovskite light‐emitting devices (LEDs) have emerged as promising candidates for bioimaging and optical communication applications. However, their performance in the air is significantly weakened by intrinsic defects and environmental instability. Here, air‐processable high‐efficiency silicon/perovskite heterostructure LEDs are demonstrated through defect engineering using 2‐phenylethyl ammonium iodide (PEAI). The PEA + cations passivate the surface defect in MAPbI 3 perovskite, resulting in a smoother surface and enhanced radiative recombination efficiency. Concurrently, this composition optimization modifies the band structure of perovskite, improving charge balance and energy level alignment within the device. The optimized devices exhibit a peak external quantum efficiency of 13.6% at 760 nm and extended operational stability (160 vs 80 min) under ambient conditions (40–60% relative humidity). The findings reveal the synergistic effects of passivation and energy level alignment induced by PEAI, providing a universal strategy for developing air‐stable, silicon‐integrated perovskite optoelectronics.