The article discusses the development of a perovskite-PCBM (phenyl-C61-butyric acid methyl ester) hybrid material that significantly reduces hysteresis and recombination loss in planar perovskite devices. The hybrid material is created through a one-step solution-processed process, where PCBM is homogeneously distributed throughout the perovskite film at grain boundaries, passivating key PbI3− antisite defects. This passivation effect is supported by theoretical and experimental evidence, including photoluminescence transient spectroscopy, which shows that PCBM promotes electron extraction. The hybrid material is demonstrated in planar solar cells, which exhibit low hysteresis and enhanced photovoltage compared to pure perovskite devices. Conductive atomic force microscopy (cAFM) studies reveal that PCBM accumulates near grain boundaries, providing continuous pathways for electron egress and suppressing hysteresis. The addition of PCBM also reduces reverse dark current and improves device performance, with the best-performing device achieving a steady-state power conversion efficiency (PCE) exceeding 14.4%. The study suggests that PCBM's role in passivating iodide-rich defects and reducing anion migration contributes to the suppression of hysteresis and improved device stability.The article discusses the development of a perovskite-PCBM (phenyl-C61-butyric acid methyl ester) hybrid material that significantly reduces hysteresis and recombination loss in planar perovskite devices. The hybrid material is created through a one-step solution-processed process, where PCBM is homogeneously distributed throughout the perovskite film at grain boundaries, passivating key PbI3− antisite defects. This passivation effect is supported by theoretical and experimental evidence, including photoluminescence transient spectroscopy, which shows that PCBM promotes electron extraction. The hybrid material is demonstrated in planar solar cells, which exhibit low hysteresis and enhanced photovoltage compared to pure perovskite devices. Conductive atomic force microscopy (cAFM) studies reveal that PCBM accumulates near grain boundaries, providing continuous pathways for electron egress and suppressing hysteresis. The addition of PCBM also reduces reverse dark current and improves device performance, with the best-performing device achieving a steady-state power conversion efficiency (PCE) exceeding 14.4%. The study suggests that PCBM's role in passivating iodide-rich defects and reducing anion migration contributes to the suppression of hysteresis and improved device stability.