ScholarWorks@동국대학교

초록

Defect-regulated interfacial electrostatics critically determine the stability and reliability of ceramic gas sensors under realistic operating environments. Here, a flexible three-dimensional Co3O4@In2O3 heterostructure integrated on O2-plasma-activated (PI) is systematically engineered to couple oxygen-vacancy modulation with chemically stabilized oxide–polymer interfaces. Dual-site Co2+↔In3+ substitution and p–n junction formation regulate carrier density and vacancy population, enabling controlled depletion-layer modulation and stable surface oxygen activation. Plasma activation introduces polar functional groups (–OH, C=O, –COOH) that form chemically bonded interfaces through hydrogen-bonding and dipolar interactions (–COO-•••M, M–OH•••O=C), reducing interfacial energy and enhancing mechanical and environmental durability. The hydrophilic interfacial layer suppresses humidity-induced performance degradation, enabling stable sensing at 95% relative humidity. Benefiting from the low thermal conductivity of PI, the device achieves stable operation at 120 °C, significantly lower than Si-supported counterparts (≥150 °C), indicating improved thermal utilization efficiency. The optimized Co3O4@In2O3/PI sensor demonstrates reliable acetone detection down to 50 ppb with rapid and reversible response characteristics and stable operation over extended mechanical deformation cycles. Time-domain resistance features coupled with machine-learning classification achieve a Macro-F1 score of 65.0% for distinguishing low (≤25 ppm) and high (≥30 ppm) exposure regimes. These results establish defect–interface co-engineering as a viable route toward mechanically robust, humidity-tolerant, and intelligent ceramic sensing platforms. Code is available at: https://github.com/Zahid672/CI-3-PI © 2024

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