Elucidation of solar cells efficiency by studying the effect of calcination on the synthesized titania nanostructured rods

by Khan, M. A.; Farva, U.

Elevating calcination conditions of 350 degrees C, 450 degrees C, 550 degrees C, 650 degrees C and 750 degrees C on the hydrothermally synthesized titania nanostructured rods were elucidated in terms of morphological change, crystallinity and photovoltaic performance. The field emission scanning electron microscopy (FE- SEM) images shows that the nanomorphology were highly stable and retains its rod structure until the 650 degrees C, although substantial increase of diameter from 16 nm (350 degrees C) to 48 nm (650 degrees C) were observed, ascribed to the sintering influence along with the decrease of surface area from 89.2 m(2) / g to 19.2 m(2) / g, respectively. The X-ray diffraction analysis shows a dominant anatase TiO 2 behavior starting from 350 degrees C to 550 degrees C with appearance of low intense 33.8 degrees, 43.9 degrees rutile peaks, while on annealing at 650 degrees C, it transforms to a dominant rutile phase with presence of low intense 25.2 degrees, 48.1 degrees anatase peaks. However, at the 750 degrees C, the tubular morphology changes to a high crystalline rutile nanoparticles with no trace of anatase phase. Each calcination condition of nanostructured rods tested in dye-sensitized solar cell giving a maximum efficiency of 6.7% at 550 degrees C. However, the sample at 750 degrees C shows a low efficiency of 1.5% due to the rutile phase, low surface area, and large grain boundaries resulting in the higher recombination's.

Surfaces and Interfaces
Start Page