Environmental influences on NDIR CO2 gas sensor using 20 % ScAlN-based pyroelectric detector chip

CO 2 gas sensors are adopted in various manufacturing industries, medical sectors and also for indoor air quality measurement. Their functions range from concentration monitoring for product quality to detecting hazardous levels for safety. Having a robust CO 2 gas sensor is important, but these sensors can be affected by temperature and humidity in the environment. Here we demonstrate an NDIR CO 2 gas sensor based on 20 % ScAlN-based pyroelectric detector chip, tested under different environmental conditions. Despite absolute signal output drop when surrounding temperatures increase, measured results show that CO 2 gas response remains the same. Moreover, relative humidity (RH) does not seem to have much effect on the response of this NDIR CO 2 gas sensor. Response times stay at ∼1–2 s despite changes in environmental conditions. This sensor is also tested continuously for 100 hours to observe its signal variation over long hours. We note signal variation of ∼± 0.44 % during the first 40 hours with subsequent variation increase to ∼ ± 1.7 % at the 50th hour. Robustness of CO 2 gas sensing with 20 % ScAlN-based pyroelectric detector chip is also observed by measuring the gas responses of 5 detector chips obtained from 5 different locations within an 8-inch wafer, measuring CO 2 gas sensing performance uniformity ∼0.48 % within an 8-inch wafer. The results obtained will allow us to have further insights and understanding on the potential and practicality of NDIR gas sensors based on 20 % ScAlN-based pyroelectric detectors when subjected to different environmental conditions.