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Quasi‐homojunction (QHJ) organic solar cells (OSCs) offer a promising alternative architecture that combines the advantages of bulk heterojunction (BHJ) and homojunction (HJ) designs. By blending a minimal fraction of donor material (a few wt%) into a nonfullerene acceptor matrix, QHJ devices can be designed to achieve efficient charge separation and transport while avoiding the morphological complexity and instability of BHJs. This study demonstrates that Y6‐based QHJ OSCs, incorporating only 4 wt% donor content, achieve a power conversion efficiency of 7.1%. This performance enhancement is enabled by replacing the PEDOT:PSS anode with a novel self‐assembled monolayer anode, which induces vertical phase separation, positioning the donor polymer at the anode interface to enhance charge extraction. The optimized vertical morphology not only facilitates efficient charge transport but also ensures excellent stability, maintaining consistent performance across active layer thicknesses of 55–180nm. This highlights the potential of QHJ architecture to combine the simplicity of HJ with the performance advantages of BHJ. Quasi‐homojunction (QHJ) organic solar cells combine the simplicity of homojunctions with the performance benefits of bulk heterojunctions. Using only 4 wt% donor material and a novel self‐assembled monolayer anode, Y6‐based QHJ devices achieve 7.1% efficiency. The optimized vertical phase separation enhances charge extraction and stability, offering a robust design across varying active layer thicknesses.