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Tailoring Ordered Mesoporous Titania Films via Introducing Germanium Nanocrystals for Enhanced Electron Transfer Photoanodes for Photovoltaic Applications |
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| Authors: | Nian Li Renjun Guo Wei Chen Volker Körstgens Julian E Heger Suzhe Liang Calvin J Brett Md Asjad Hossain Jianshu Zheng Peter S Deimel Ali Buyruk Francesco Allegretti Matthias Schwartzkopf Jonathan G C Veinot Guido Schmitz Johannes V Barth Tayebeh Ameri Stephan V Roth Peter Müller-Buschbaum |
| Affiliation: | 1. Lehrstuhl für Funktionelle Materialien, Physik-Department, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany;2. Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22603 Hamburg, Germany
Department of Engineering Mechanics, KTH Royal Institute of Technology, Teknikringen 8, Stockholm, 100 44 Sweden Wallenberg Wood Science Center, KTH Royal Institute of Technology, Teknikringen 56–58, Stockholm, 100 44 Sweden;3. Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2E1 Canada;4. Institute of Materials Science, University of Stuttgart, Heisenbergstr. 3, 70569 Stuttgart, Germany;5. Physik-Department, Lehrstuhl für Molekulare Nanowissenschaften & Chemische Physik von Grenzflächen, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany;6. Chair of Physical Chemistry, Department of Chemistry, University of Munich (LMU), Butenandtstr. 11, 81377 Munich, Germany;7. Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22603 Hamburg, Germany;8. Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22603 Hamburg, Germany Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56–58, Stockholm, 100 44 Sweden |
| Abstract: | Based on a diblock-copolymer templated sol–gel synthesis, germanium nanocrystals (GeNCs) are introduced to tailor mesoporous titania (TiO2) films for obtaining more efficient anodes for photovoltaic applications. After thermal annealing in air, the hybrid films with different GeNC content are investigated and compared with films undergoing an argon atmosphere annealing. The surface and inner morphologies of the TiO2/GeOx nanocomposite films are probed via scanning electron microscopy and grazing-incidence small-angle X-ray scattering. The crystal phase, chemical composition, and optical properties of the nanocomposite films are examined with transmission electron microscopy, X-ray photoelectron spectroscopy, and ultraviolet–visible spectroscopy. Special focus is set on the air-annealed nanocomposite films since they hold greater promise for photovoltaics. Specifically, the charge–carrier dynamics of these air-annealed nanocomposite films are studied, and it is found that, compared with pristine TiO2 photoanodes, the GeNC addition enhances the electron transfer, yielding an increase in the short-circuit photocurrent density of exemplary perovskite solar cells and thus, an enhanced device efficiency as well as a significantly reduced hysteresis. |
| Keywords: | enhanced electron transfer germanium nanocrystals ordered mesoporous nanostructures photoanodes titania |