【作者】:Zhao Peilu,Wang Lian,Liu Deye,Li Dan,Sun Peng ,Liu Fengmin*, Lu Geyu*
【题目】:Branched hierarchical titanium dioxide nanoflower on carbon nanofiber with efficient scattering layer for high performance dye-sensitized solar cells
【关键词】:Dye-sensitized solar cells, Carbon nanofiber/titanium oxide composite materials,Hollow sphere, Bilayered photoanode, High power conversion efficiency
【版面信息】:"Electrochimica Acta 182 (2015) 257-263"
摘要:
A new bilayered photoanode is fabricated for dye-sensitized solar cells (DSSCs) composed of the carbon nanofiber coated by hierarchical TiO2nanoflower (CNF-TNF) as underlayer and the urchin-like TiO2hollow sphere (UTHS) as light-scattering layer. The CNF-TNF with a large specific surface area of 336.5 m2g-1provides dual-functions of more dye loading and efficient charge transport, leading to the enhanced short-circuit photocurrent density of 21.40 mA cm-2and prolonged electron lifetime of 189.2 ms. The incorporated carbon nanofiber not only reduces the interfacial resistance and the charge recombination rate, but also improves the light harvesting, resulting in a high photoelectric conversion efficiency (PCE) up to 8.57% for the single-layered CNF-TNF based DSSC. In addition, by optimizing the surface morphology of TiO2hollow sphere, we obtain the unique 3D UTHS, exhibiting strong light-scattering effect and low charge recombination due to the favorable connection among spheres provided by modified porous shell. As a consequence, an overall PCE of 9.21% is achieved for CNF-TNF+UTHS based DSSC, which is far superior to that of P25 based DSSC (5.10%). To the best of our knowledge, it is the first time that the hierarchically CNF-TNF composite is synthesized and utilized for enhanced efficiency DSSCs.