Surface-Enhanced Infrared Absorption-Based CO2 Sensor using Photonic Crystal Slab

Surface-enhanced infrared absorption (SEIRA) technique has been focusing on the metallic resonator structures for decades while the dissipative loss and strong heating from metal are the intrinsic drawbacks. Meanwhile, gas sensor is also challenging for SEIRA because of the small size and weak absorption of gas. This paper reports an all dielectric photonic crystal slab (PCS) platform integrated with gas selective enrichment polymer polyethylenimine (PEI) as a miniaturized gas sensor, achieving a detection limit of 20 ppm and a fast response time of 2 min in CO
₂
sensing.