Impedance Spectroscopy Analysis of the Effect of TiO2 Blocking Layers on the Efficiency of Dye Sensitized Solar Cells

The introduction of a dense TiO2 layer between the mesoporous TiO2 network and the charge collector in dye-sensitized solar cell anodes has been claimed to improve the performance of solar cell devices. Two mechanisms have been proposed to explain this behavior, a decrease in the electron–hole recombination at substrate/electrolyte interface and an enhancement in the electronic contact between the mesoporous TiO2 network and the charge collecting electrode. In this work the effect of sputtered TiO2 blocking layers (BLs) on the performance of dye-sensitized solar cells electrodes has been analyzed. It has been shown that the electron injection efficiency governed changes observed in cell efficiency. The thicker the BL, the poorer the photocurrent, and therefore, only thin BLs leaded to an increase in energy conversion efficiencies. The thickness of the BL also affected the internal series resistance of the solar cells, influencing their fill factor.

[1]  Anders Hagfeldt,et al.  Investigation of influence of redox species on the interfacial energetics of a dye-sensitized nanoporous TiO2 solar cell , 1998 .

[2]  Michael Grätzel,et al.  Highly efficient mesoscopic dye-sensitized solar cells based on donor-acceptor-substituted porphyrins. , 2010, Angewandte Chemie.

[3]  Qing Wang,et al.  Characteristics of high efficiency dye-sensitized solar cells. , 2006, The journal of physical chemistry. B.

[4]  Juan Bisquert,et al.  Influence of electrolyte in transport and recombination in dye-sensitized solar cells studied by impedance spectroscopy , 2005 .

[5]  David Emin,et al.  High mobility n‐type charge carriers in large single crystals of anatase (TiO2) , 1994 .

[6]  Juan Bisquert,et al.  Decoupling of Transport, Charge Storage, and Interfacial Charge Transfer in the Nanocrystalline TiO2/Electrolyte System by Impedance Methods , 2002 .

[7]  Juan Bisquert,et al.  Chemical capacitance of nanostructured semiconductors: its origin and significance for nanocomposite solar cells , 2003 .

[8]  Chuan He,et al.  Electrochemical Impedance Spectroscopy Characterization of Electron Transport and Recombination in ZnO Nanorod Dye-Sensitized Solar Cells , 2009 .

[9]  Qing Wang,et al.  Dependence of Dye-Sensitized Solar Cell Impedance on Photoelectrode Thickness , 2012 .

[10]  A. Zaban,et al.  Internal Photoreference Electrode: A Powerful Characterization Method for Photoelectrochemical Quantum Dot Sensitized Solar Cells , 2011 .

[11]  Tina C. Li,et al.  Surface passivation of nanoporous TiO 2 via atomic layer deposition of ZrO 2 for solid-state dye-sensitized solar cell applications , 2009 .

[12]  Th. Dittrich,et al.  Electron Drift Mobility in Porous TiO2 (Anatase) , 1998 .

[13]  R. Chang,et al.  Materials, interfaces, and photon confinement in dye-sensitized solar cells. , 2010, The journal of physical chemistry. B.

[14]  Valery Shklover,et al.  Nanocrystalline titanium oxide electrodes for photovoltaic applications , 2005 .

[15]  Peng Wang,et al.  Dye-Sensitized Solar Cells with a High Absorptivity Ruthenium Sensitizer Featuring a 2-(Hexylthio)thiophene Conjugated Bipyridine , 2009 .

[16]  J. van Deelen,et al.  Microstructure characterization of titanium dioxide nanodispersions and thin films for dye-sensitized solar cell devices , 2004 .

[17]  F. Fabregat‐Santiago,et al.  Characterization of nanostructured hybrid and organic solar cells by impedance spectroscopy. , 2011, Physical chemistry chemical physics : PCCP.

[18]  P. R. Bueno,et al.  Synthesis and characterization of mesoporous TiO2 nanostructured films prepared by a modified sol–gel method for application in dye solar cells , 2011 .

[19]  Qing Wang,et al.  Electrochemical impedance spectroscopic analysis of dye-sensitized solar cells. , 2005, The journal of physical chemistry. B.

[20]  Juan Bisquert,et al.  Breakthroughs in the Development of Semiconductor-Sensitized Solar Cells , 2010 .

[21]  F. Fabregat‐Santiago,et al.  Electronic conductivity in nanostructured TiO2 films permeated with electrolyte , 2003 .

[22]  A. O. Patrocinio,et al.  Layer-by-layer TiO2 films as efficient blocking layers in dye-sensitized solar cells , 2009 .

[23]  M. Grätzel,et al.  A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films , 1991, Nature.

[24]  L. Peter,et al.  How does back-reaction at the conducting glass substrate influence the dynamic photovoltage response of nanocrystalline dye-sensitized solar cells? , 2005, The journal of physical chemistry. B.

[25]  L. Bourgeois,et al.  Characterization of nanostructured core-shell working electrodes for application in dye-sensitized solar cells , 2005 .

[26]  Michael Grätzel,et al.  Dye-Sensitized Core−Shell Nanocrystals: Improved Efficiency of Mesoporous Tin Oxide Electrodes Coated with a Thin Layer of an Insulating Oxide , 2002 .

[27]  Takayuki Kitamura,et al.  Influence of TiO2 Nanoparticle Size on Electron Diffusion and Recombination in Dye-Sensitized TiO2 Solar Cells , 2003 .

[28]  Shozo Yanagida,et al.  Deposition of a thin film of TiOx from a titanium metal target as novel blocking layers at conducting glass/TiO2 interfaces in ionic liquid mesoscopic TiO2 dye-sensitized solar cells. , 2006, The journal of physical chemistry. B.

[29]  Fumin Wang,et al.  Highly efficient dye-sensitized solar cells with a titania thin-film electrode composed of a network structure of single-crystal-like TiO2 nanowires made by the "oriented attachment" mechanism. , 2004, Journal of the American Chemical Society.

[30]  N. Park,et al.  Chemically deposited blocking layers on FTO substrates: Effect of precursor concentration on photovoltaic performance of dye-sensitized solar cells , 2010 .

[31]  Peng Wang,et al.  High-efficiency dye-sensitized solar cells: the influence of lithium ions on exciton dissociation, charge recombination, and surface states. , 2010, ACS nano.

[32]  Seigo Ito,et al.  Control of dark current in photoelectrochemical (TiO2/I--I3-)) and dye-sensitized solar cells. , 2005, Chemical communications.

[33]  E. Barea,et al.  Energetic factors governing injection, regeneration and recombination in dye solar cells with phthalocyanine sensitizers , 2010 .

[34]  Anders Hagfeldt,et al.  Characteristics of the iodide/triiodide redox mediator in dye-sensitized solar cells. , 2009, Accounts of chemical research.

[35]  H. Grubin.  The physics of semiconductor devices , 1979, IEEE Journal of Quantum Electronics.

[36]  Dai Songyuan,et al.  Mechanism of Enhanced Performance of Dye-Sensitized Solar Cell Based TiO 2 Films Treated by Titanium Tetrachloride , 2004 .

[37]  Juan Bisquert,et al.  Correlation between Photovoltaic Performance and Impedance Spectroscopy of Dye-Sensitized Solar Cells Based on Ionic Liquids , 2007 .

[38]  Juan Bisquert,et al.  Physical Chemical Principles of Photovoltaic Conversion with Nanoparticulate, Mesoporous Dye-Sensitized Solar Cells , 2004 .

[39]  H. Goto,et al.  Carrier leakage blocking effect of high temperature sputtered TiO2 film on dye-sensitized mesoporous photoelectrode , 2007 .

[40]  Juan Bisquert,et al.  Theory of the Impedance of Electron Diffusion and Recombination in a Thin Layer , 2002 .

[41]  Laurence M. Peter,et al.  Characterization of titanium dioxide blocking layers in dye-sensitized nanocrystalline solar cells , 2003 .