TY - JOUR
T1 - Synthesis and characterization of thieno[3,4-d]imidazole-based organic sensitizers for photoelectrochemical cells
AU - Karthik, Durai
AU - Kumar, Vijay
AU - Justin Thomas, K. R.
AU - Li, Chun Ting
AU - Ho, Kuo Chuan
N1 - Funding Information:
Financial support from CSIR (Ref. No. 02/(0230)/15/EMR-II dated 05-06-2015), New Delhi to KRJT is gratefully acknowledged and DST for HRMS facility via FIST Program to the Chemistry Department. DK thanks UGC, New Delhi for research fellowship.
Publisher Copyright:
© 2016 Elsevier Ltd. All rights reserved.
PY - 2016/6/1
Y1 - 2016/6/1
N2 - Six organic sensitizers containing thieno[3,4-d]imidazole chromophore were synthesized and characterized by photophysical, electrochemical and photovoltaic studies. N-alkylated derivatives containing thiophene substituents showed blue-shifted absorption when compared to the dyes containing 4-tert-butyl-phenyl group attributable to the disturbance in the conjugation due to tilting in the structure. However, the former dyes exhibited red-shifted absorption when anchored on TiO2 due to enhanced aggregation. All dyes displayed negative solvatochromism in the absorption spectra indicating the charge transfer character and polar ground state. They exhibited low oxidation potentials than the dyes, known in the literature, which possess imidazole-based donor. Among the dyes, a dye containing bithiophene in the conjugation and thiophenes on thieno[3,4-d]imidazole nucleus showed best photovoltaic performance with η = 2.78%, Jsc = 7.91 mA cm-2 and ff = 0.63. Electrochemical impedance spectroscopy studies on the devices established the relationship between the functional chromophores on the electron injection and electron recombination kinetics.
AB - Six organic sensitizers containing thieno[3,4-d]imidazole chromophore were synthesized and characterized by photophysical, electrochemical and photovoltaic studies. N-alkylated derivatives containing thiophene substituents showed blue-shifted absorption when compared to the dyes containing 4-tert-butyl-phenyl group attributable to the disturbance in the conjugation due to tilting in the structure. However, the former dyes exhibited red-shifted absorption when anchored on TiO2 due to enhanced aggregation. All dyes displayed negative solvatochromism in the absorption spectra indicating the charge transfer character and polar ground state. They exhibited low oxidation potentials than the dyes, known in the literature, which possess imidazole-based donor. Among the dyes, a dye containing bithiophene in the conjugation and thiophenes on thieno[3,4-d]imidazole nucleus showed best photovoltaic performance with η = 2.78%, Jsc = 7.91 mA cm-2 and ff = 0.63. Electrochemical impedance spectroscopy studies on the devices established the relationship between the functional chromophores on the electron injection and electron recombination kinetics.
KW - Dye-sensitized solar cells
KW - Electrochemical impedance spectra
KW - Optical spectra
KW - Organic dyes
KW - TDDFT computations
KW - Thieno[3,4-d]imidazole
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U2 - 10.1016/j.dyepig.2016.02.009
DO - 10.1016/j.dyepig.2016.02.009
M3 - Article
AN - SCOPUS:84959019105
SN - 0143-7208
VL - 129
SP - 60
EP - 70
JO - Dyes and Pigments
JF - Dyes and Pigments
ER -
