Solution-derived 40 µm vertically aligned ZnO nanowire arrays as photoelectrodes in dye-sensitized solar cells

Well-aligned ZnO nanowire arrays with a long length of more than 40 microm were prepared successfully by using the polyethylenimine (PEI)-assisted preheating hydrothermal method (PAPHT). Several important synthetic parameters such as PEI content, growth time, preheating time and zinc salt concentration were found to determine the growth of ultralong ZnO nanowire arrays, including length, diameter, density and alignment degree. The photoluminescence (PL) spectrum of as-grown ultralong ZnO nanowire arrays revealed a UV emission and a yellow emission, which was attributed to the absorbed hydroxyl group based on the peak shift after annealing in various atmospheres. The performance of dye-sensitized solar cells (DSSCs) increased with increasing length of ZnO nanowire arrays, which was mainly ascribed to the aggrandized photocurrent and reduced recombination loss according to electrochemical impedance spectroscopy (EIS). A maximum efficiency of 1.3% for a cell with a short-circuit current density (J(sc)) = 4.26 mA cm(2), open-circuit voltage (V(oc)) = 0.69 V and (fill factor) FF = 0.42 was achieved with a length of 40 microm.

[1]  G. Hu,et al.  Hydrothermal synthesis of ZnO nanorod arrays with the addition of polyethyleneimine , 2008 .

[2]  Kam Sing Wong,et al.  Defect emissions in ZnO nanostructures , 2007 .

[3]  Huifang Xu,et al.  Complex and oriented ZnO nanostructures , 2003, Nature materials.

[4]  G. Cao,et al.  Effects of Dye Loading Conditions on the Energy Conversion Efficiency of ZnO and TiO2 Dye-Sensitized Solar Cells , 2007 .

[5]  D. Riley,et al.  Mechanism of ZnO nanotube growth by hydrothermal methods on ZnO film-coated Si substrates. , 2006, The journal of physical chemistry. B.

[6]  L. Vayssieres.  Growth of Arrayed Nanorods and Nanowires of ZnO from Aqueous Solutions , 2003 .

[7]  Jianfeng Chen,et al.  Novel ZnO-Based Film with Double Light-Scattering Layers as Photoelectrodes for Enhanced Efficiency in Dye-Sensitized Solar Cells† , 2010 .

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

[9]  E. Aydil,et al.  Dye-sensitized solar cells based on semiconductor morphologies with ZnO nanowires , 2006 .

[10]  Sang Yeol Lee,et al.  Annealing effect on the property of ultraviolet and green emissions of ZnO thin films , 2004 .

[11]  Y. Liu,et al.  Excitonic properties of ZnO nanocrystalline films prepared by oxidation of zinc-implanted silica , 2004 .

[12]  R. Katoh,et al.  Electron Injection Efficiency from Excited N3 into Nanocrystalline ZnO Films: Effect of (N3−Zn2+) Aggregate Formation , 2003 .

[13]  G. Hu,et al.  Epitaxy of Vertical ZnO Nanorod Arrays on Highly (001)-Oriented ZnO Seed Monolayer by a Hydrothermal Route , 2008 .

[14]  Song-Yeu Tsai,et al.  Formation of Branched ZnO Nanowires from Solvothermal Method and Dye-Sensitized Solar Cells Applications , 2008 .

[15]  Gareth M. Fuge,et al.  Synthesis of Aligned Arrays of Ultrathin ZnO Nanotubes on a Si Wafer Coated with a Thin ZnO Film , 2005 .

[16]  Anders Hagfeldt,et al.  PES Studies of Ru(dcbpyH2)2(NCS)2 Adsorption on Nanostructured ZnO for Solar Cell Applications , 2002 .

[17]  San-Yuan Chen,et al.  Synthesis and optical properties of white-light-emitting alumina/ZnO nanotubes , 2008, Nanotechnology.

[18]  Guo-Qiang Lo,et al.  Improved dye-sensitized solar cells with a ZnO-nanoflower photoanode , 2007 .

[19]  J. Boland,et al.  Controllable Growth of ZnO Nanostructures by a Simple Solvothermal Process , 2008 .

[20]  Wai Kin Chan,et al.  Different origins of visible luminescence in ZnO nanostructures fabricated by the chemical and evaporation methods , 2004 .

[21]  Peidong Yang,et al.  Nanowire dye-sensitized solar cells , 2005, Nature materials.

[22]  Study of Dye-Sensitized Solar Cells by Scanning Electron Micrograph Observation and Thickness Optimization of Porous TiO2 Electrodes , 2009 .

[23]  Aleksandra Radenovic,et al.  ZnO-Al2O3 and ZnO-TiO2 core-shell nanowire dye-sensitized solar cells. , 2006, The journal of physical chemistry. B.

[24]  Eray S. Aydil,et al.  Nanowire-based dye-sensitized solar cells , 2005 .

[25]  Guozhong Cao,et al.  Aggregation of ZnO nanocrystallites for high conversion efficiency in dye-sensitized solar cells. , 2008, Angewandte Chemie.

[26]  Peidong Yang,et al.  Solution-grown zinc oxide nanowires. , 2006, Inorganic chemistry.

[27]  Yun Chi,et al.  New Family of Ruthenium‐Dye‐ Sensitized Nanocrystalline TiO2 Solar Cells with a High Solar‐Energy‐Conversion Efficiency , 2007 .

[28]  Simon P Ringer,et al.  Three-dimensional electrodes for dye-sensitized solar cells: synthesis of indium–tin-oxide nanowire arrays and ITO/TiO2 core–shell nanowire arrays by electrophoretic deposition , 2009, Nanotechnology.

[29]  K. Tennakone,et al.  A high efficiency indoline-sensitized solar cell based on a nanocrystalline TiO(2) surface doped with copper. , 2008, Nanotechnology.

[30]  Joseph T Hupp,et al.  ZnO nanotube based dye-sensitized solar cells. , 2007, Nano letters.

[31]  Juan Bisquert,et al.  Doubling Exponent Models for the Analysis of Porous Film Electrodes by Impedance. Relaxation of TiO2 Nanoporous in Aqueous Solution , 2000 .