N-type conjugated polymers (CPs) are essential building blocks for high-performance organic electronics. While the incorporation of ammonium additives is a key strategy to optimize morphology and charge transport, their practical application is limited by poor miscibility with the polymer matrix. In this study, we introduce ether-functionalized ammonium salts (EGBr) as a novel additive to optimize the benchmark n-type polymer, N2200. Experimental results demonstrate an electron (μe) of 1.09 cm2 V–1 s–1, which is a four-fold increase over the control (0.272 cm2 V–1 s–1). Furthermore, when the modified N2200 films are applied to organic photodiodes (OPDs) as electron transporting layer, the EGBr-incorporated N2200 achieved a specific detectivity (D*shot) of 2.11 × 1013 cm Hz0.5 W–1, and outperforming the alkyl-based ammonium salt-incorporated film (8.31 × 1012 cm Hz0.5 W–1) and the control (3.79 × 1012 cm Hz0.5 W–1).