Tuning the bandgap of Zn1−xMnxO thin films prepared by the sol-gel method

The morphology and optical properties of Zn_1-xMn_xO films were synthesized by sol gel method using spin coating technique. Zn_1-xMn_xO thin films is prepared using 2-methoxyethanol solution of zinc acetate dehydrate and manganese acetate tetrahydrate. The solution is stabilized by MEA. The quantity of Mn in the sol was varied from x = 0,0.02, 0.04, 0.06 and 0.08 with annealing temperature of 600°C. Investigation of the physical properties and presence of nanostructures were executed using SEM and XRD characterization. Addition of Mn lead to the formation of nanosize rod structures. The optical properties were characterized using UV-Vis where the band gap and transmittance can be determined. Results show that the transmittance spectra and band gap reduces after a certain percentage of Mn addition. The variation of the band gap performance with dopant concentration is also examined.