Effects of AlN film thickness and operating frequency on sensing output of CO₂ pyroelectric-based non-dispersive infrared gas sensor

Carbon dioxide(CO2) is a greenhouse gas that not only cause impact to climate but could also affect health when sick building syndrome(SBS) kicks in. Here, we sense CO2 using a pyroelectric-based non-dispersive infrared(NDIR) gas sensor. The pyroelectric sensing layer used is aluminum nitride(AlN). To understand the behaviour of AlN-based pyroelectric detectors on CO2 gas sensing, we vary the AlN film thickness and operating frequency of the pyroelectric detector. We note ~50% change in signal response when AlN film thickness reduces. The results will provide more understanding on characteristics of AlN-based pyroelectric detectors and their behaviours in NDIR gas sensing.