Sensing of Ethanol with Nanosize Fe-ZnO Thin Films

Abstract EN

Sensing of ethanol with iron doped ZnO (Fe-ZnO) thin films has been studied in this work.

By X-ray diffraction spectroscopy, it is found that ZnO is the main compound in the low-iron (<10%) doped ZnO thin films.

ZnFe2O4 is also found as 20–50% of iron are doped on the thin films.

The 5% Fe-ZnO thin film has a very high sensitivity (Rair/Rethanol>70) to 1000 ppm of ethanol at 300 K.

It seems that iron can promote the sensivity of the ZnO thin film.

The thin film doped with a greater amount (20–50%) of iron has, however, a much less sensitivity (<15) to ethanol.

The chemical interactions between oxygen of ethanol and zinc on the Fe-ZnO thin film cause changes of the bond distances of Zn–O and Fe–O in the thin films to 1.90 and 1.98 Å which can be restored to 1.91 and 1.97 Å, respectively, in the absence of ethanol.