High-Performance Temperature Sensors for Early Warning Utilizing Flexible All-Inorganic Thermoelectric Films.

The demand for highly sensitive temperature-response materials is critical for the advancement of intelligent temperature sensing and fire warning systems. Despite notable progress in thermoelectrical (TE) materials and devices, designing TE materials suitable for wide-range temperature monitoring across diverse scenarios remains a challenge. In this study, we introduce a TE temperature sensor for fire warnings and hot object recognition, utilizing an all-inorganic TE film composite of reduced graphene oxide (rGO)/Te nanowires (Te NWs). The resulting all-inorganic TE film, annealed at a high temperature, exhibits distinct response ratios to varying temperature changes, enabling consistently sensitive thermosensation. The robust linear relationship between open circuit voltage and temperature difference establishes it as an effective thermoreceptor for enhanced temperature alerts. Furthermore, we demonstrate that the assembled TE sensor provides rapid high-temperature warnings with adjustable threshold voltages (1-7 mV), achieving an ultrafast response time of approximately 4.8 s at 1 mV threshold voltage. Additionally, this TE sensor can be integrated with the gloves to monitor high-temperature objects in various scenarios, such as the brewed milk in daily life and heating reactors in industrial applications. These results offer perspectives for future innovations in intelligent temperature monitoring.