Reducing mass-transport limitations in cobalt-electrolyte-based dye-sensitized solar cells by photoanode modification
Trang Pham, Thi Thu
Koh, Teck Ming
Lam, Yeng Ming
Mhaisalkar, Subodh G.
Date of Issue2014
School of Materials Science and Engineering
Energy Research Institute
Mass transport has been identified as a limiting problem in the photovoltaic performance of dye-sensitized solar cells based on electrolytes consisting of ionic liquids or cobalt complexes. A mixed TiO2 macroporous–mesoporous morphology employed as photoanode is demonstrated to assist the diffusion of electrolytes with higher viscosity or consisting of bulky redox mediators, such as cobalt di-tert-butyl bipyridine [Co(dtb)3]2+/3+. This morphology with large pores improves the non-linearity of photocurrent response to light intensity indicating better diffusion. The incorporated sub-micrometer pores also reduce recombination and decrease diffusion resistance, as revealed by electrochemical impedance spectroscopy.
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