Electrical and Optical studies on emerging nanostructures for high efficiency photovoltic device applications

Abstract

Vast number of research is going around the globe for generating sustainable alternate source of renewable energy. It is well known that an abundant source of solar energy is available and is eco-friendly. Scientists have designed a number of varieties of solar cells, among them Dye-Sensitized Solar Cells (DSSCs) are observed to be simple construction, non-hazards to the environment, and shows good performance under ambient light. Dye Sensitized Solar Cells (DSSCs - Gratzel cell) are the third generation thin film solar cells which are emerging photovoltaic techniques to produce electricity. This bionic model of the photo electrochemical cell is composed of dye coated nano porous photoanode which is sandwiched together with a counter electrode to catalyze the (reduce) electrolyte with electrons from the external circuit. Ever since this type of cell emerges (1991) as an efficient device, there has been a mammoth growth in the development of DSSCs in all respects over the past three decades. At first (in 60s) DSSCs were demonstrated with the metal oxide electrodes like ZnO, TiO2, and SnO2 etc. which are sensitized with Chlorophyll and derivatives of the chlorophyll and Rose Bengal. It is important to mention that Sb-doped SnO2 (ATO) exhibits good optical property, high electrical conductivity and stability, all favourable points to be used as photoanode in a solar cell. Though several literatures are available on DSSC with TiO2 photoanode (without dye), it could absorb only 6 7% of the solar spectrum. Hence, an alternative ATO can be used as the photoanode. Moreover, tin and antimony are abundant on earth and low cost materials with an excellent optoelectrical property. newline