High temperature coefficient of resistance material with metal-doped nanoporous carbon for low-temperature sensor

A high temperature coefficient of resistance (TCR) material with exceptional sensitivity in low-temperature regions (below 100°C) was successfully developed using metal-doped hybrid nanoporous carbon (HNPC). These materials, synthesized through metal-organic framework-based pyrolysis, exhibit a negative TCR of −9331.69 ppm·°C⁻¹ (−0.933 %·°C⁻¹), comparable to graphene-based temperature sensors. By maintaining consistent molar ratios while varying solution volumes, we produced HNPCs with controlled sizes (approximately 200 nm and 800 nm) and systematically altered nanopore structures. Brunauer–Emmett–Teller analysis revealed that variations in pore structure significantly influenced particle size and pore volume, directly impacting electrical properties through altered charge carrier mobility—the key mechanism behind the material's high thermal sensitivity. The discontinuities in the nanoporous network create electron transport barriers that respond sensitively to temperature changes, enhancing TCR performance. These materials offer advantages in stable formation, uniformity, and scalability for large-area device fabrication. Current applications include substrate-based platforms such as interdigitated electrode chips with micrometer-scale electrode gaps. With further optimization of electrode spacing and packaging techniques, these materials can be effectively utilized in biosensor and environmental monitoring applications. Nonetheless, achieving consistent performance across large-scale production remains a significant challenge.