TY - JOUR
T1 - The influence of charge transport and recombination on the performance of dye-sensitized solar cells
AU - Wang, Mingkui
AU - Chen, Peter
AU - Humphry-Baker, Robin
AU - Zakeeruddin, Shaik M.
AU - Grätzel, Michael
PY - 2009/1/12
Y1 - 2009/1/12
N2 - Electrochemical impedance spectroscopy (EIS) and transient voltage decay measurements are applied to compare the performance of dye sensitized solar cells (DSCs) using organic electrolytes, ionic liquids and organic-hole conductors as hole transport materials (HTM). Nano-crystalline titania films sensitized by the same heteroleptic ruthenium complex NaRu(4-carboxylic acid-4′-carboxylate) (4,4′-dinonyl-2,2′-bipyridyl)(NCS) 2 , coded Z-907Na are employed as working electrodes. The influence of the nature of the HTM on the photovoltaic figures of merit, that is, the open circuit voltage, short circuit photocurrent and fill factor is evaluated. In order to derive the electron lifetime, as well as the electron diffusion coefficient and charge collection efficiency, EIS measurements are performed in the dark and under illumination corresponding to realistic photovoltaic operating conditions of these mesoscopic solar cells. A theoretical model is established to interpret the frequency response off the impedance under open circuit conditions, which is conceptually similar to photovoltage transient decay measurements. Important information on factors that govern the dynamics of electron transport within the nanocrystalline TiO2 film and charge recombination across the dye sensitized heterojunction is obtained.
AB - Electrochemical impedance spectroscopy (EIS) and transient voltage decay measurements are applied to compare the performance of dye sensitized solar cells (DSCs) using organic electrolytes, ionic liquids and organic-hole conductors as hole transport materials (HTM). Nano-crystalline titania films sensitized by the same heteroleptic ruthenium complex NaRu(4-carboxylic acid-4′-carboxylate) (4,4′-dinonyl-2,2′-bipyridyl)(NCS) 2 , coded Z-907Na are employed as working electrodes. The influence of the nature of the HTM on the photovoltaic figures of merit, that is, the open circuit voltage, short circuit photocurrent and fill factor is evaluated. In order to derive the electron lifetime, as well as the electron diffusion coefficient and charge collection efficiency, EIS measurements are performed in the dark and under illumination corresponding to realistic photovoltaic operating conditions of these mesoscopic solar cells. A theoretical model is established to interpret the frequency response off the impedance under open circuit conditions, which is conceptually similar to photovoltage transient decay measurements. Important information on factors that govern the dynamics of electron transport within the nanocrystalline TiO2 film and charge recombination across the dye sensitized heterojunction is obtained.
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U2 - 10.1002/cphc.200800708
DO - 10.1002/cphc.200800708
M3 - Article
C2 - 19115326
AN - SCOPUS:58149529431
VL - 10
SP - 290
EP - 299
JO - ChemPhysChem
JF - ChemPhysChem
SN - 1439-4235
IS - 1
ER -