SYNTHESIS OF MESOPOROUS TITANIUM DIOXIDE FILMS FOR DYE-SENSITIZED SOLAR CELLS

Abstract

Porous solid films offering large specific surface area and well connected cavities have been researched extensively in the last decade, aiming to enhance photo-conversion efficiency in the dye-sensitised solar cells (DSSCs). Generally, the photo-conversion efficiency of DSSCs is very sensitive to surface morphology, crystallinity and porosity of the film which are in turn highly dependent upon fabrication protocol. Preservation of ordered mesoporous structure is essential for increasing surface area in the films and is reported to be highly sensitive to pre-curing temperature. Ti02 films were synthesised using layer-by- layer deposition in combination with block-polymer templating. The pre-curing temperature was varied between 200-300° Celsius for fabricating different sets of films. Influence of varying the pre-curing temperature on morphology and interfaces of film layers was investigated using AFM, SEM, EDX and UV-VIS Spectrophotometer. Also, a modified method of pre-curing temperature was employed successfully, in order to attain firm adhesiveness of the film to the conducting glass substrate, even at lower pre-curing temperatures below 250°C. The films prepared by different pre-curing temperature protocols were incorporated into DSSCs for evaluating its influence on the photo-conversion efficiency of the cells.