Self-powered gas sensor using thin-film photovoltaic cell and microstructured colorimetric film

We have developed a self-powered gas sensor operating without external power under a light source, unlike a sensor that requires an external power source, such as a chemiresistive gas sensor or an electrochemical gas sensor. The sensor consists of a colorimetric film and an organic solar cell. The sensor uses a color change caused by the reaction of the N, N,N',N'-tetramethyl-p-phenylenediamine (TMPD) with NO 2 gas. The color change caused by the redox reaction of the colorimetric material does not require a separate light source and photodetector, unlike the conventional colorimetric sensor, because it directly changes the output of the solar cell by changing the transmittance of the film. Using this sensor, 1, 5, 10, 20ppm NO 2 gas was detected without external power source, and the performance of the gas sensor could be improved by using microstructure. This work is the first demonstration of self-powered gas sensor based on the combination of photovoltaic cell and microstructured colorimetric film.