Fig. 5: Detection in air using a tandem polymer concept.
From: Inverse designed plasmonic metasurface with parts per billion optical hydrogen detection
a Δλpeak response to stepwise decreasing H2 concentration (1000–0.25 ppm) diluted in synthetic air at room temperature. Inset: zoomed-in version of the sensor response to 250 ppb H2. b Measured Δλpeak as a function of H2 concentration derived from (a). Gray dashed line is a guide to the eye. Light gray symbols are the response of the optimized sensor (i.e. without PVOH) in Ar (cf. Fig. 4b). The red dashed line marks the 3σ value (0.03 nm). Inset: To-scale schematic of the tandem sensor comprising a 5 nm PVOH film (orange), acting as an O2 barrier, on a 295 nm PMMA layer (green). The tandem sensor shows a similar response to the optimized sensor measured in Ar.
