A New Approach to Grow A-TiO<sub>2</sub> Nanocubes

Abstract

The vertically aligned TiO2 Nanotubes (TiNTs) extracts electrons from an absorber and also helps in its transport in perovskite and dye sensitized solar cells (DSSCs) solar cells. Thus electron transporting layer plays a very important role in photon to electron conversion. Electrochemical anodization is been used widely to grow TiNTs for solar cell applications; due to its low cost, flexibility to vary pore diameter and tube length. We observed that, TiNTs maintained its tubular array only for a set time period. On increasing the growth time they begin to take the form of nanocrystals with {001} facets. Formation of these titanium nanocrystals (TiNcs) was clearly observed through field emission scanning electron microscope (FESEM) and Transmission electron microscopy (TEM). Thus TiO2 nanostructures can be tuned by varying anodization time. More importantly, optimization of the reaction process led to the growth of more orderly, crystalline anatase TiNTs/TiNcs over Ti metal foil substrate. The crystal structure and surface morphology of the prepared thin film samples were studied using X-ray diffraction (XRD) technique and scanning and transmission electron microscopes (TEM). XRD confirmed the anatase phase of as grown TiO2 with (101) as major intensity preferred orientation. Lattice parameters calculated were found to be a= 3.77-to-3.82 and c= 9.42-to-9.58 for grown TiO2.