Nanostructured copper oxides as ethanol vapour sensors

We report onethanol(C2 H5 OH) vapour sensingdevicesbasedonnanostructuredcupric oxide (CuO) and cuprous oxide (Cu2 O)thin films, which are deposited using RF sputtering at relatively low temperature and power conditions: at 120◦ C, single stoichiometry CuO and Cu2 O films are deposited using the sputtering power of 200 and 250W, respectively. At such sputtering conditions CuO films exhibit smaller nanocrystallite base dimensions (∼30nm), in comparison to Cu2 O films (∼85nm), which significantly enhance surface area to volume ratio. Both nanostructured CuO and Cu2 O gas sensors are able to detect ethanol vapour as low as several ppm and at relatively low operating temperatures of 180 and 260◦ C, respectively.The sensors showedhighsensitivity andrepeatability, aswell as fast response andrecovery towards ethanol vapour.