Amorphous molybdenum trioxide thin films for gas sensing applications

Uniform and smooth substoichiometric Molybdenum trioxide (MoO3−x) films have been achieved via thermal evaporation technique. MoO3 thin films were deposited onto glass and fluorine doped tin oxide (FTO) coated glass slides. The field-emission scanning electron microscopy micrographs reveal the amorphous behavior for films deposited either on glass or FTO substrates. The two thicknesses 500 and 650 nm of MoO3−x films which are deposited on glass and FTO coated glass slides were electrically examined as sensors towards NO,CO2 and HCl gases. The sensing process have been explained based on the electrical dipole layer formation consisting of the two unlike charged ion- layers and causing an energy band bending at the surface region of the film as a result of the gas adsorption. MoO3−x films on glass substrate is a perfect sensor towards oxidizing CO2 and NO gasses. The sensors are very …