کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
78544 49336 2012 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Electrochemical design of ZnO hierarchical structures for dye-sensitized solar cells
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Electrochemical design of ZnO hierarchical structures for dye-sensitized solar cells
چکیده انگلیسی

ZnO single-crystalline nanowires (NWs) are highly relevant 1D-nanostructures for efficient charge collection in dye sensitized solar cells (DSSCs). In a first part of the paper, ZnO-NWs have been grown by electrochemistry on various fluorine-doped transparent oxide (FTO) coated glass substrates. The effects of substrate treatments and of the presence of an underlayer of TiO2 or ZnO on the cell performance are reported. In particular, we show that the presence of a TiO2 underlayer gives rise to a dense array of ZnO-NWs with a high aspect ratio (>30) and to the cells with the best performances. However, the roughness of the NW arrayed films were not sufficient for the efficient harvesting of sunlight and low fill factors were found. In a second step, hierarchical structures have been designed by growing electrochemically a secondary nanoporous epitaxial ZnO phase on the wire surface. We have found that the cell performances were significantly improved in that case due to a much larger specific surface area and to a much better fill factor. We also show that the cell efficiencies of hierarchical structures did not follow the performances of the starting ZnO-NWs. The volume occupied by the second phase, its thickness and its connection to the wires are important parameters for cell optimizing.


► We have studied the effect of FTO on ZnO nanowires arrays grown by electrodeposition.
► Hierarchical structures have been designed, epitaxially combining ZnO nanowires and a porous ZnO phase.
► Dye-sensitized solar cells have been fabricated from these structures and characterized.
► Optimized composite structure gave rise to a power conversion efficiency of 4.1%.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Solar Energy Materials and Solar Cells - Volume 102, July 2012, Pages 8–14
نویسندگان
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