Controllable Efficient 3D/2D Perovskite Polycrystalline Heterojunction for Record-Performance Mixed-Cation Horizontal Photodetector

The 3D/2D perovskite film vertical heterojunction (3D/2D PFVH) has emerged as a promising candidate for high-performance photodetectors, as it overcomes the limitations of mono-perovskite while preserving their photoelectric properties and enhancing active layer stability, surface defect passivation, and carrier dynamics. However, controllable and cost-effective fabrication of efficient 3D/2D PFVH remains challenging. Herein, an improved hot-pressing reaction transfer-assisted method is proposed to successfully prepare high-quality 3D/2D PFVH after optimizing pressure and concentration. A carrier dynamics model is also proposed to elucidate the changes in defect states, carrier dynamics, and photophysical properties during the formation of 3D/2D PFVH. Furthermore, the efficient 3D/2D PFVH under optimal conditions exhibited remarkable enhancements in photoluminescence, carrier lifetime, humidity stability, and defect mitigation. Ultimately, the champion 3D/2D PFVH horizontal photodetector achieved a record-performance in photo-responsivity (R up to 4.59 A/W) and external quantum efficiency (EQE up to 1.07 × 10 3 %), signifying their superior light detection capabilities. This study offers valuable insights for designing high-quality 3D/2D PFVH for advanced high-performance planar optoelectronic devices for multiple scenes.