Chandrasekharam Malapaka

Abstract:

As fossil fuels are quickly depleting, there is a search for alternative energy resources such as solar energy. An advantage of the Dye Sensitized Solar Cells (DSSC) with respect to competing technologies, is that its performance is remarkably insensitive to temperature change and incident angle of solar light. Thus, raising the temperature from 20 to 600C has practically no effect on the power conversion efficiency. Further, DSSC are known to work with the same efficiency even under diffused light conditions. In contrast, conventional silicon cells exhibit a significant decline over the same temperature range amounting to 20%. The best photovoltaic performance among DSSCs, both in terms of conversion yield and long term stability, has so far been achieved with polypyridyl complexes of ruthenium. The high efficiencies of the ruthenium(II)-polypyridyl DSSCs can be attributed to their wide absorption range from the visible to the near infra-red (NIR) regime. We have been engaged in the synthesis and evaluation of stable and efficient new metal free organic, phthalocyanine as well as ruthenium based dyes as sensitizers for DSSC application. We also achieved a certified world record efficiency of 11.40% employing a simple co-adsorbent in a black dye based device designed and developed at IICT.