Effect of microwave sintering on the crystal domain and electrical properties of TiO2 nanoparticles

Abstract

We report the effect of microwaves sintering on the crystal domain and electrical properties of TiO2 nanoparticles. Commercially available TiO2 nanoparticles of 25 nm size were coated on ITO (indium tin oxide) substrates, which were then sintered at 450 C employing microwave and conventional sintering approaches. The structural properties of the sintered coatings were examined using atomic force microscopy (AFM), scanning electron microscope (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDS), whereas the charge transfer properties were investigated using electrochemical impedance spectroscopy (EIS). Structural analysis reveals that the microwave sintering of TiO2-coated substrates results in the formation of more ordered crystal structure as compared to the conventionally sintered samples. Nyquist plots demonstrate the improved charge transfer characteristics of TiO2 nanoparticles in microwave-sintered layers. Also, the application of the microwave-sintered TiO2-coated ITO substrates as photoanode in dye-sensitized solar cells (DSSCs) confirms superior electrical properties compared to conventionally sintered samples.