An efficient photonic crystal-based chemical sensor for the detection of isopropanol, ethanol, and acetone

For the improvement of daily needs, the use of many chemicals is growing rapidly. Some of these compounds are harmful to human health. Moreover, due to the wide range of applications in industry, it has become necessary to develop rapid and accurate detectors for chemical compounds. Herein, a new chemical photonic structure is theoretically investigated as a detector for isopropanol, ethanol, and acetone. The proposed sensor is based on a 1D ternary photonic crystal and has the structure (Si/Si${}_3$N${}_4$/SiO${}_2$)${}^N$/cavity layer/(Si/Si${}_3$N${}_4$/SiO${}_2$)${}^N$. The organic chemical compounds are assumed to be separately infiltrated into the cavity layer. The defect layer (DLR) thickness, incident angle, number of unit cells, and the contrast between the high- and low-index layers are varied and the sensitivity and quality factor are found for each case. The sensitivity can be considerably improved by increasing the DLR thickness, angle of incidence, and the contrast between the high- and low-index materials. An extremely high sensitivity (2270.48, 2283.0555, and 2283.75) and quality factor (21.82 × 10${}^5$, 21.48 × 10${}^5$ and 21.46 × 10${}^5$) are obtained for isopropanol, ethanol, and acetone. The results described earlier may pave the way for a practical and useful method of diagnosing chemical compounds. (© 2023 Wiley‐VCH GmbH)