Preparation of Cr-doped TiO_2 thin film of P-type conduction for gas sensor application

摘要

Titanium dioxide (TiO_2) could be doped with as much as 8.7% atom% Cr by meansof a sol-gel method.XRD analysis revealed that the powder of Cr(8.7 atom%)-doped TiO_2 calcined at 500degC consisted of small crystallites ascribale to anatase structure.The thin film of doped TiO_2 (70 mum) at this composition was found to behave as a p-type semiconductor on exposure to CO and NO_2 inair:it responded to dilute NO_2 with a sharp decrease in electrical resistance.