Evaluation of structural and optical properties of TeO2 nano and micro structures grown on glass and silicon substrates using thermal evaporation method

A facile evaporation method is employed to synthesize different morphologies of TeO2 using Te powder as the source material, and glass and silicon as the growth substrates. The morphological, structural, and optical properties of the obtained TeO2 products are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and ultraviolet-visible (UV-vis) analyses. The morphology change of TeO2 structures is investigated by changing the evaporation temperature and substrate type. The diameters of nanowires and microrods grown on the Si substrate through this method are in the range of 50-460 nm, while the lengths of these products are several tens of micrometers. For the glass substrate, the morphology of TeO2 products is a mixture of nano- and micro-sheets. The high-temperature process facilitates the thickening of the sheets, nanowires, and nanorods. The presented energy dispersive X-ray of the TeO2 products confirms the formation of TeO2. The variation of the absorption of TeO2, coated on glass and Si substrates, with evaporation temperature is investigated. The band gap of the samples is calculated using UV-vis spectra; the results show a reduction in the band gap with increasing evaporation temperature. Furthermore, Raman analysis is performed in the present study.