Interpenetrating Polymer Semiconductor Nanonetwork Channel for Ultrasensitive, Selective, and Fast Recovered...

Organic semiconductor (OSC)-based gas detection has attracted considerable attention due to the facile manufacturing process and effective contact with target chemicals at room temperature. However, OSCs intrinsically suffer from inferior sensing and recovery capability due to lack of functional sites and deep gas penetration into the film. Here, we describe an interpenetrating polymer semiconductor nanonetwork (IPSN) channel possessing unreacted silanol (Si-OH) groups on its surface to overcome bottlenecks that come from OSC-based chemodetection. On the top of the IPSN, moreover, we introduced electron-donating amine (NH₂) groups as a chemical receptor because they strongly interact with the electron-withdrawing nature of NO₂ gas. The NH₂-IPSN-based field-effect transistor exhibited high-performance chemodetection such as ultrasensitivity (990% ppm^-1 at 5 ppm) and excellent NO₂ selectivity against other toxic gases. Impressively, the gas recovery was significantly improved because the NH₂ chemical receptors anchored on the surface of the IPSN suppress deep gas penetration into the film. This work demonstrates that our NO₂ chemodetection is expected to provide inspiration and guideline for realization of practical gas sensors in various industries and daily life.