Enhanced Capacitive Humidity Sensing Performance at Room Temperature via Hydrogen Bonding of Cyanopyridone-Based Oligothiophene Donor

Cyanopyridone-based oligothiophene donors with both hydrophobic and hydrophilic characters have been evaluated as active layers within simple capacitive devices for humidity sensing at room temperature. Surface studies using atomic force microscopy revealed a self-assembled nanofibrous network thin needle-like structure the terminal hydroxy example (CP6), devoid in methyl (CP1). The performance of each sensor was investigated over broad range relative levels function capacitance CP6 demonstrated favourable features such high sensitivity (12.2 pF/%RH), quick response/recovery (13 s/20.7 s), wide working (10%–95% RH), low hysteresis (0.57%), outstanding recyclability, excellent long-term stability. From results obtained, hydrophilicity hydrogen bonding appear to play vital role enhancing performance, leading possible new design directions organic semiconductor-based sensors.