Ethanol sensing properties of nitrogen doped-In2O3 thin films

Nitrogen doped Indium oxide-(In2O3) thin films have been investigated for their suitability as a potential sensor for the detection of ethanol vapour. With urea as a precursor, N-In2O3 thin films of various thicknesses have been synthesised by sol-gel technique. The response transients of the films have been found to follow Freundlich adsorption isotherm from the conductance transient analysis. The heat of adsorption (Q) and adsorption activation energy (Ea) have been estimated for the films. Further, ethanol sensing performance of the N-In2O3 films have been found to depend strongly on their microstructure. A significantly large sensing response (Ra/Rg similar to 313 for 300 ppm ethanol) have been recorded for similar to 250 nm thick N-In2O3 film for which the heat of adsorption has been the highest. Two leading factors, namely the modification of surface electron distribution and effective surface areas, have been suggested to regulate the ethanol sensing properties of N-In2O3 thin films.

Automated summary

The study found that the ethanol sensing performance of N-doped Indium oxide thin films is strongly dependent on their microstructure, with adsorption heat being a key factor influencing ethanol sensing response.