Fabrication of deterministic charge conductive paths in dye-sensitized solar cells

• Main Author: Tey, Yew Hown.
• Other Authors: Wong, Chee Cheong
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Materials::Energy materials
• Online Access: http://hdl.handle.net/10356/15416
• Institution: Nanyang Technological University

This research is focused on the fabrication of three-dimensional (3D) deterministic Indium Tin Oxide (ITO) charge conductive paths to improve the energy conversion efficiency of Dye Sensitized Solar Cells (DSSC). One of the major issues faced by many researchers leading to low conversion efficiency is the loss of photo-generated electrons through electron recombination mechanism in the mesoporous Titanium Dioxide (TiO2) film. Thus, a 3D conducting electrode (CE) path has been implemented to reduce the recombination effect. The report will discuss the fabrication of the 3D ITO structure and the implementation of such structure in the DSSC. The most important accomplishment of this work is to obtain a 3D ITO ordered structure by employing colloidal self-assembly and sol-gel techniques. The assembled Polystyrene (PS) template has a face cubic centered (FCC) structure which acts as a backbone to produce the deterministic ITO structure while the inorganic metal salts solution provides the material, ITO. The composition of the 3D structure produced consisted of 26 % of indium oxide (In2O3) and 74 % of tin (IV) oxide (SnO2). The ITO infiltration was monitored with a reflectance spectrometer to achieve an optimum filling and finally the sheet resistance of the IO was measured to be 21 MΩ/□. The experiment revealed that the sheet resistance of the IO layer decreases as the In2O3 content increases. Different amounts of TiO2 were demonstrated to be filled into the interstices of the 3D. The application of the 3D ITO structure in DSSC allows an intimate contact between the mesoporous TiO2 and conducting electrode itself allowing the generated electrons to be transferred into the external circuit more readily. To conclude, this report has shown that the fabrication of a deterministic 3D ITO conducting electrode pathway is possible. This kind of structure could be applied to DSSCs to improve the conversion efficiency of the cells thereby bringing the advancement of DSSC to the next level.