UV Light-Modulated Fluctuation-Enhanced Gas Sensing by Layers of Graphene Flakes/TiO₂ Nanoparticles

Figure 5

Normalized product of frequency and power spectral density of voltage fluctuations across a gas sensor biased by a DC voltage when the sensor was in an ambient atmosphere of (a) synthetic air (S.A.) and (b) 15 ppm of NO₂ diluted in S.A. The operating temperature was . The sensing layer (graphene flakes/TiO₂ ratio 10 wt%) was working in the dark and under UV light supplied by LEDs with emission wavelengths of 362 nm (LED 1) and 394 nm (LED 2).

(a)

(b)