Graphene high-temperature sensors based on segmented annealing process

Temperature sensors play a vital role in industrial automation, environmental surveillance, and consumer electronics, where precise thermal monitoring is essential for operational reliability and safety. However, traditional temperature sensors are typically unable to function effectively beyond a temperature range of 200 °C, limiting their practical applications for the detection of high-temperature in extreme environments. Herein, we present a thermal protection method involving the growth of a silicon nitride (Si₃N₄) protective layer on graphene surfaces followed by thermal annealing to enhance its thermal stability and durability. Using this technique, a graphene-based high-temperature sensor with excellent performance was successfully fabricated, effectively addressing the issue of graphene's susceptibility to oxidation at elevated temperatures while preventing contamination by impurities. Segmented annealing could alleviate thermally induced stress accumulation and suppresses passivation cracking/bubbling, enabling stable operation in ambient air up to 1250 °C. Moreover, the graphene-based high-temperature sensor demonstrates a broad temperature measurement range, excellent resistance consistency, and a compact design, making it well-suited for diverse applications. And the proposed thermal protection method offers new insights into the design and fabrication of high-temperature sensors, demonstrating significant potential in applications requiring high-temperature endurance, such as aircraft engines and oil wells.