A Rational Design of Isoindigo‐Based Conjugated Microporous n‐Type Semiconductors for High Electron Mobility and Conductivity

Abstract

The development of n‐type organic semiconductors has evolved significantly slower in comparison to that of p‐type organic semiconductors mainly due to the lack of electron‐deficient building blocks with stability and processability. However, to realize a variety of organic optoelectronic devices, high‐performance n‐type polymer semiconductors are essential. Herein, conjugated microporous polymers (CMPs) comprising isoindigo acceptor units linked to benzene or pyrene donor units (BI and PI) showing n‐type semiconducting behavior are reported. In addition, considering the challenges of deposition of a continuous and homogeneous thin film of CMPs for accurate Hall measurements, a plasma‐assisted fabrication technique is developed to yield uniform thin films. The fully conjugated 2D networks in PI‐ and BI‐CMP films display high electron mobility of 6.6 and 3.5 cm² V⁻¹ s⁻¹, respectively. The higher carrier concentration in PI results in high conductivity (5.3 mS cm⁻¹). Both experimental and computational studies are adequately combined to investigate structure–property relations for this intriguing class of materials in the context of organic electronics.