TY - JOUR
T1 - From flat to nanostructured photovoltaics
T2 - Balance between thickness of the absorber and charge screening in sensitized solar cells
AU - Boix, Pablo P.
AU - Lee, Yong Hui
AU - Fabregat-Santiago, Francisco
AU - Im, Sang Hyuk
AU - Mora-Sero, Ivan
AU - Bisquert, Juan
AU - Seok, Sang Il
PY - 2012/1/24
Y1 - 2012/1/24
N2 - Figure Persented: Nanoporous metal oxide electrodes provide a high internal area for dye anchoring in dye-sensitized solar cells, but the thickness required to extinguish the solar photons also enhances recombination at the TiO 2/electrolyte interface. The high extinction coefficient of inorganic semiconductor absorber should allow the reduction of the film thickness, improving the photovoltage. Here we study all-solid semiconductor sensitized solar cells, in the promising TiO 2/Sb 2S 3/P3HT configuration. Flat and nanostructured cells have been prepared and analyzed, developing a cell performance model, based on impedance spectroscopy results, that allows us to determine the impact of the reduction of metal oxide film thickness on the operation of the solar cell. Decreasing the effective surface area toward the limit of flat samples produces a reduction in the recombination rate, increasing the open circuit potential, V oc, while providing a significant photocurrent. However, charge compensation problems as a consequence of inefficient charge screening in flat cells increase the hole transport resistance, lowering severely the cell fill factor. The use of novel structures balancing recombination and hole transport will enhance solid sensitized cell performance.
AB - Figure Persented: Nanoporous metal oxide electrodes provide a high internal area for dye anchoring in dye-sensitized solar cells, but the thickness required to extinguish the solar photons also enhances recombination at the TiO 2/electrolyte interface. The high extinction coefficient of inorganic semiconductor absorber should allow the reduction of the film thickness, improving the photovoltage. Here we study all-solid semiconductor sensitized solar cells, in the promising TiO 2/Sb 2S 3/P3HT configuration. Flat and nanostructured cells have been prepared and analyzed, developing a cell performance model, based on impedance spectroscopy results, that allows us to determine the impact of the reduction of metal oxide film thickness on the operation of the solar cell. Decreasing the effective surface area toward the limit of flat samples produces a reduction in the recombination rate, increasing the open circuit potential, V oc, while providing a significant photocurrent. However, charge compensation problems as a consequence of inefficient charge screening in flat cells increase the hole transport resistance, lowering severely the cell fill factor. The use of novel structures balancing recombination and hole transport will enhance solid sensitized cell performance.
KW - TiO /Sb S /P3HT
KW - dye-sensitized solar cells
KW - nanostructured cells
KW - photovoltaics
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U2 - 10.1021/nn204382k
DO - 10.1021/nn204382k
M3 - Article
C2 - 22175224
AN - SCOPUS:84856189357
VL - 6
SP - 873
EP - 880
JO - ACS Nano
JF - ACS Nano
SN - 1936-0851
IS - 1
ER -