Photodissociation-driven photoacoustic spectroscopy with UV-LEDs for ozone detection

This study presents the development and evaluation of a UV-LED based photoacoustic (PA) measurement system for ozone (O₃) detection to demonstrate its potential for low-cost and accurate sensing while for the first time addressing the importance of photodissociation for PA signal generation for O₃ in the UV range. With a detection limit of 7.9 ppbV, the system exhibits a significant advancement over state-of-the-art UV-PA O₃ detection and is on par with laser-based setups. Following a novel discussion of the PA signal arising from photodissociation and its products, cross-sensitivity effects due to environmental factors such as temperature and gas composition were systematically analyzed. A digital twin driven compensation for these influences was implemented and evaluated. Despite the challenges associated with modeling the effects of H₂O and CO₂, the PA system shows considerable potential, though further studies in real world applications must be conducted.