| 초록 |
In this study, we describe a simple selective etching method that produces noncurling, freestanding, large-area, aligned TNTs with both ends opened. The novel selective etching process only removed the thin 2nd bottom layer from the physically and chemically stable thick amorphous 1st top layer under thermal treatment at 250°C, yielding ordered doubly open-ended TNTs that could be easily transferred to an FTO substrate for the fabrication of front-illuminated dye sensitized solar cells (DSCs). The TNT-DSCs yielded a higher PCE (8.6%) than was observed from TiO2 nanoparticle-based DSCs (7.3%), for comparable film thicknesses of 16 micro meter. Intensity-modulated photocurrent and photovoltage spectroscopy (IMPS and IMVS, respectively) revealed that the TNT-DSCs exhibited electron lifetimes that were 10 times longer than those of TNP-DSCs, which contributed to high device performances. |
