Polytetrafluoroethylene-Inspired Intrinsically Moisture-Resistant Semiconductor for Gas Sensing

Water molecules in ambient air readily adsorb on semiconductor dangling bonds and polar sites, perturbing charge transport and degrading electrical performance and stability. Achieving moisture resistance without compromising electronic function and surface activity remains a fundamental challenge. Inspired by polytetrafluoroethylene, we introduce a symmetry-driven dipole-cancellation strategy to design an intrinsically moisture-resistant semiconductor, Cd-NTP. In Cd-NTP structure, centrosymmetric alignment of nitrobenzene (sensing functional group) along the Cd-S backbone suppresses the net dipole to 0.07 Debye, affording a water contact angle of 136°. As a proof of concept, Cd-NTP chemiresistive sensor exhibits an 852% response to 100 ppm NH3 at room temperature with only 4% variation across 10–90% RH. This moisture-resistant performance surpasses that of current state-of-the-art single-component materials and commercial devices. This work establishes a molecular design strategy that decouples hydrophobicity from electronic performance, providing a viable pathway toward moisture-resistant semiconductor applications.