Investigation of structural and optical properties of spin coated TiO2:Mn thin films

Abstract

In the current work, we have deposited and studied various properties of spin coated undoped and Mn doped TiO 2 films annealed at 400 °C on glass substrate. The influence of Mn dopant concentrations on the properties of TiO 2 thin film is detailed. X-ray Diffraction (XRD), Raman spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Atomic Force Microscopy (AFM), UV–Vis spectroscopy and Photoluminescence (PL) studies were carried out to determine the structural parameters, surface morphology/topography and optical properties of TiO 2 films. The XRD pattern of both undoped and TiO 2 :Mn thin films have exhibited (101) plane as a preferential orientation confirming the presence of anatase phase and same reflected in the Raman study. AFM image analysis reveals an improvement in surface roughness with an increase in Mn concentration indicating the coalescence of smaller crystallites. FESEM image analysis also confirmed the effect of Mn on surface morphology. UV–Vis spectroscopic measurements indicated a red shift of absorption edge upon doping. Refractive index calculation confirmed the densification of the films with increase in Mn concentration. From the PL study, luminescence property of TiO 2 was found to improve upon Mn doping. • Mn doped TiO 2 thin films were successfully deposited by spin coating method. • XRD and Raman measurements demonstrate the presence of the pure anatase phase. • Mn doping induced defects such as vacancies and interstitials are reported. • TiO 2 :Mn thin films can be used for enhanced UV photodegradation of organic dyes.