Improved recovery time and sensitivity to H(2) and NH(3) at room temperature with SnO(x) vertical nanopillars on ITO

Nanostructured SnO(2) is a promising material for the scalable production of portable gas sensors. To fully exploit their potential, these gas sensors need a faster recovery rate and higher sensitivity at room temperature than the current state of the art. Here we demonstrate a chemiresistive gas sensor based on vertical SnO(x) nanopillars, capable of sensing < 5 ppm of H(2) at room temperature and 10 ppt at 230 °C. We test the sample both in vacuum and in air and observe an exceptional improvement in the performance compared to commercially available gas sensors. In particular, the recovery time for sensing NH(3) at room temperature is more than one order of magnitude faster than a commercial SnO(2) sensor. The sensor shows an unique combination of high sensitivity and fast recovery time, matching the requirements on materials expected to foster widespread use of portable and affordable gas sensors.