Mesoscopic solar cells based on nanostructured oxide semiconductors are considered as a promising candidates to replace conventional photovoltaics employing costly materials. However, their overall performances are below the sufficient level required for practical usages. Herein, this study proposes an anodized Ti foam (ATF) with multidimensional and hierarchical architecture as a highly efficient photoelectrode for the generation of a large photocurrent. ATF photoelectrodes prepared by electrochemical anodization of freeze-cast Ti foams have three favorable characteristics: (i) large surface area for enhanced light harvesting, (ii) 1D semiconductor structure for facilitated charge collection, and (iii) 3D highly conductive metallic current collector that enables exclusion of transparent conducting oxide substrate. Based on these advantages, when ATF is utilized in dye-sensitized solar cells, short-circuit photocurrent density up to 22.0 mA cm−2 is achieved in the conventional N719 dye-I3 −/I− redox electrolyte system even with an intrinsically inferior quasi-solid electrolyte.
Bibliographical noteFunding Information:
Y.-E.S. acknowledges financial support from the Institute for Basic Science (IBS) in Republic of Korea (Project Code: IBS-R006-G1 and IBS-R006-D1). H.C. acknowledges supports from the Basic Science Research Program (2014R1A2A1A11052513), and the Priority Research Centers Programs (2012-0006680) through the National Research Foundation (NRF) of Korea. The authors give thanks to Dr. Yasumasa Chino at Materials Research Institute for Sustainable Development, the National Institute of Advanced Industrial Science and Technology (AIST) in Japan for fabrication of the titanium foam during his stay in Northwestern University as a visiting scholar.
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- metal foams
- solar cells
- titanium dioxide
ASJC Scopus subject areas
- Materials Science(all)