Sol–Gel Dip Coating Method Synthesis of Mn-Doped Titanium Dioxide Thin Films

Abstract

Undoped and Mn-doped TiO2 thin films have been prepared by sol–gel dip-coating technique on glass and silicon substrates. X-ray diffraction studies showed that both TiO2 and Mn-doped TiO2 thin films are of anatase phase with (101) as preferential orientation. All films exhibit high transparency ([Formula: see text]80%) over the visible range. The optical bandgap decreases from 3.66[Formula: see text]eV to 3.52[Formula: see text]eV due to the extent of electronic states introduced by doping. Infrared transmission spectra showed Ti–O (625[Formula: see text]cm[Formula: see text]) and Ti–O–Ti (495–436[Formula: see text]cm[Formula: see text]) bands. Thermal analysis revealed endothermic reactions between 94∘C and 110∘C and exothermic reactions between 406∘C and 443∘C. The Nyquist plots depicted that equivalent circuit of the films is an [Formula: see text] parallel. The resistance [Formula: see text] decreases while the capacitance [Formula: see text] increases with Mn-doping.