Fabrication of double layer photoelectrodes using hierarchical TiO2 nanospheres for dye-sensitized solar cells

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) 2012, 18(1), , pp.449-455
• Main Authors: Park, Jung Tae, Roh, Dong Kyu, Chi, Won Seok, Patel, Rajkumar, Kim, Jong Hak
• Format: Article
• Language: English
• Subjects: Double layer; Dyes; Electrolytic cells; Nanospheres; Performance enhancement; Photovoltaic cells; Solar cells; Titanium dioxide; 화학공학
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2011.11.029

Double layer photoelectrodes consisting of the TiO2 nanoparticles (npTiO2) with 30-40 nm in diameter and the TiO2 nanospheres (nsTiO2) with 100-200 nm as a bottom and a top layer, respectively, were fabricated for dye-sensitized solar cells (DSSCs) employing a polymer electrolyte. The nsTiO2 with hierarchical pores were prepared via the combined process of atom transfer radical polymerization (ATRP) and a sol-gel. Use of nsTiO2 resulted in the remarkable enhancement of cell performance due to light scattering and dye adsorption capability. The overall energy conversion efficiency ( eta ) of 5.5% was achieved by the formation of npTiO2-nsTiO2 double layer photoelectrode, which was higher than those formed by npTiO2 alone (4.6%) or nsTiO2-nsTiO2 double layer (4.4%). Electrochemical impedance spectra (EIS) analysis showed that the npTiO2-nsTiO2 double layer had lower electron transfer resistance and longer electron lifetime, leading to facilitation of reduced recombination and consequently improvement of cell performance.