Detachment and transfer of ordered TiO2 nanotube arrays for front-illuminated dye-sensitized solar cells
2011; Royal Society of Chemistry; Volume: 4; Issue: 9 Linguagem: Inglês
10.1039/c0ee00474j
ISSN1754-5706
AutoresLu-Lin Li, Yi‐Ju Chen, Hui‐Ping Wu, Niann S. Wang, Eric Wei‐Guang Diau,
Tópico(s)Transition Metal Oxide Nanomaterials
ResumoWe report a method of detachment and transfer of one-dimensional TiO2 nanotube (NT) arrays to fabricate dye-sensitized solar cells (DSSCs) with illumination from the front side. The ordered NT arrays (tube length 20 μm) were detached from the NT–Ti substrate, as annealed, by means of a second anodization at 20 V for 4 h and then transferred, inverted, onto a transparent substrate of conducting oxide (TCO) with an interface of TiO2 nanoparticles of thickness ∼2 μm. Dry etching of the NT surface in a highly dense plasma reactor under BCl3/Cl2 for 90 s opened previously closed ends of the tubes. The inverted (bottom-up) NT–TCO substrate was fabricated into a DSSC device that shows a cell performance (η = 6.24%) significantly improved over those of a front-illuminated counterpart with an upright (face-up) structure (η = 4.84%) and of a conventional back-illuminated device (η = 4.61%). Electrochemical impedance spectra (EIS) of the devices under one-sun irradiation were measured to rationalize the cell performances that are consistent with the corresponding interfacial impedances between the NT arrays and the electrode for collection of electrons.
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