Reducing mass-transport limitations in cobalt-electrolyte-based dye-sensitized solar cells by photoanode modification

• Main Authors: Mhaisalkar, Subodh Gautam, Trang Pham, Thi Thu, Koh, Teck Ming, Nonomura, Kazuteru, Lam, Yeng Ming, Mathews, Nripan
• Other Authors: School of Materials Science and Engineering
• Format: Article
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering
• Online Access: https://hdl.handle.net/10356/106663; http://hdl.handle.net/10220/19625
• Institution: Nanyang Technological University

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.