Switching of Electron and Ion Conductions by Reversible H₂O Sorption in n-Type Organic Semiconductors

Polar H2O molecules generally act as trapping sites and suppress the electron mobility of n-Type organic semiconductors, making chemical design of H2O-Tolerant and responsive n-Type semiconductors an important step toward multifunctional electron-ion coupling devices. The introduction of effective electrostatic interactions between potassium ions (K+) and carboxylate (-COO-) anions into the electron-Transporting naphthalenediimide I-framework enables the design of high-performance H2O-Tolerant n-Type semiconductors with a reversible H2O adsorption-desorption ability, where the electron mobility and K+ ionic conductivity were coupled with the reversible H2O sorption behavior. The reversible H2O adsorption into the crystals enhanced the electron mobility from 0.04 to 0.28 cm2 V-1 s-1, whereas the K+ ionic conductivity decreased from 3.4 × 10-5 to 4.7 × 10-7 S cm-1. Because this reversible electron-ion conducting switch is responsive to H2O sorption behavior, it is a strong candidate for H2O gating carrier transport systems.