Study on Dye Sensitized Solar Cells for Improved Performances

Abstract

This thesis is focused on the improvement of performance of DSC. Unique materias as Zno, odered mesoporous carbon, graphene-metal nonoparticle composit was introduced to DSC to deveolp the performance. In this thesis ZnO with novel nanostructure was introdueced with adventage of large surface area and good morphology for penetrating of the dye solution. This work provides intriguing way of structurally designing of ZnO with large surface area and moderate morphology for DSSCs and other applications. rGO/metal nanoparticle hybrid films and OMC–CNT, where the primary particles of the OMCs are interconnected via the CNTs are introduced for counter electrodes in DSC as Pt replacement counter electrode. The enhanced electrochemical stability of the Au nanoparticles on rGO was attributed to the unique combination of the presence of defects as well as hydroxyl and carboxyl functional groups. the OMC–CNT-based cell showed an excellent cell efficiency which was primarily attributed to its remarkably enhanced electrical conductivity as well as its intrinsic catalytic activity. This work provides an intriguing way of structurally designing a low-cost, Pt-free, high-performance counter electrode material for DSC. New coating method for DSC working-electrode is introduced, too. The method controls the reaction temperatures with concentrations of N719 in various solvents. Sorts of alcohols and DMSO was invetigaed and can be ideally applied to shorten the coating time to only 3 min which is much improved from the several hour scale needed for the conventional solvents such as acetonitrile and ethanol. The cells were compared by characterization with JV measurement, dye uptake amount, DRIFT, and EIS. Performance and other characteristics of the cells with working electrodes prepared by this new methods were very comparable to those prepared by conventional methods.