The Polymer Society of Korea

Abstract

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 (μ_e) 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 Hz^0.5 W^–1, and outperforming the alkyl-based ammonium salt-incorporated film (8.31 × 10¹² cm Hz^0.5 W^–1) and the control (3.79 × 10¹² cm Hz^0.5 W^–1).