Premium
Structural and Electrical Properties of Nb‐Doped Anatase TiO 2 Nanowires by Electrospinning
Author(s) -
Archana Panikar S.,
Jose Rajan,
Jin Tan Mein,
Vijila Chellapan,
Yusoff Mashitah M.,
Ramakrishna Seeram
Publication year - 2010
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2010.04003.x
Subject(s) - materials science , anatase , doping , chemical engineering , nanowire , electrospinning , dopant , annealing (glass) , dye sensitized solar cell , titanium , titanium dioxide , nanotechnology , photocatalysis , composite material , metallurgy , optoelectronics , chemistry , polymer , catalysis , biochemistry , electrode , engineering , electrolyte
One‐dimensional nanostructures of niobium‐doped anatase TiO 2 (Nb:TiO 2 ) up to 5 at.% Nb were synthesized by electrospinning a polymeric solution containing titanium and niobium precursors and subsequent annealing. Thus obtained fibers had diameter ∼150 nm. The undoped TiO 2 fibers were constituted by larger single crystalline grains of size ∼50 nm, whereas the doped ones had decreased grain sizes (∼30 nm) under similar processing conditions. The Nb doping decreased the BET surface area of TiO 2 . A strain‐induced lattice contraction was observed in Nb:TiO 2 . The continuous nanofibers were shortened to nanowires (NW) of aspect ratio 10:1 by ultrasonically dispersing them in acetic acid, which were developed as films of thickness ∼8–13 μm onto conducting glass substrates. The TiO 2 and Nb:TiO 2 nanowire films were further sensitized by a dye; the amount of dye anchored was found to decrease with increase in the dopant concentration. The dye‐sensitized solar cells fabricated using the doped fibers, although with a nominally increased current density ( J SC ), have reduced efficiency due to lower fill factor and open circuit voltage ( V OC ). The electron diffusion coefficient ( D n ) and mobility (μ n ) of the TiO 2 and Nb:TiO 2 NW in the presence of iodide/triiodide ions were an order of magnitude higher compared with the undoped samples.