TY - JOUR
T1 - Electrochemical approach to enhance the open-circuit voltage (Voc) of dye-sensitized solar cells (DSSCs)
AU - Nath, Narayan Chandra Deb
AU - Lee, Ho Joon
AU - Choi, Won Youl
AU - Lee, Jae Joon
PY - 2013
Y1 - 2013
N2 - The net enhancement of open-circuit voltage (Voc) of dye-sensitized solar cells (DSSCs) was achievedwith the novel electrolyte composed of interhalogen based binary-redox couples without regard to thechoice of sensitizers. The interhalogen ion, I2Br-, was formed in the conventional iodine-based elec-trolyte by both chemically and electrochemically and it was found to produce an extra redox pair, (I -,Br-)/I2Br-, with new energy state at a more positive potential than that of I-/I3 -. The Fermi level of theelectrolyte shifted positively by the weighted-average of the two redox systems. It induced the increase of V oc up to 30, 60, and 50 mV for cis-diisothiocyanato-bis(2,2′- bipyridyl-4,4′-dicarboxylato) ruthenium(II)bis(tetrabutylammonium) (N719), cis-dicyano-bis(2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium(II)(Ruthenizer 505 or Ru505), and 2′,4′,5′,7′- tetrabromofluorescein (eosin Y) dyes, respectively, withoutaffecting the short circuit current much. It corresponded to the enhancement of the overall power con-version efficiency (η) up to 8, 14, and 13%, respectively. Moreover, the degree of enhancement of Voc was controllable by varying [I 2Br-] since the higher the contribution of [I 2Br-] the more positive shift in theenergy level of the binary redox couples.
AB - The net enhancement of open-circuit voltage (Voc) of dye-sensitized solar cells (DSSCs) was achievedwith the novel electrolyte composed of interhalogen based binary-redox couples without regard to thechoice of sensitizers. The interhalogen ion, I2Br-, was formed in the conventional iodine-based elec-trolyte by both chemically and electrochemically and it was found to produce an extra redox pair, (I -,Br-)/I2Br-, with new energy state at a more positive potential than that of I-/I3 -. The Fermi level of theelectrolyte shifted positively by the weighted-average of the two redox systems. It induced the increase of V oc up to 30, 60, and 50 mV for cis-diisothiocyanato-bis(2,2′- bipyridyl-4,4′-dicarboxylato) ruthenium(II)bis(tetrabutylammonium) (N719), cis-dicyano-bis(2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium(II)(Ruthenizer 505 or Ru505), and 2′,4′,5′,7′- tetrabromofluorescein (eosin Y) dyes, respectively, withoutaffecting the short circuit current much. It corresponded to the enhancement of the overall power con-version efficiency (η) up to 8, 14, and 13%, respectively. Moreover, the degree of enhancement of Voc was controllable by varying [I 2Br-] since the higher the contribution of [I 2Br-] the more positive shift in theenergy level of the binary redox couples.
KW - Dye-sensitized solar cell
KW - Electrolyte
KW - Fermi level
KW - Interhalogen
KW - Redox couple
UR - http://www.scopus.com/inward/record.url?scp=84881015709&partnerID=8YFLogxK
U2 - 10.1016/j.electacta.2013.07.057
DO - 10.1016/j.electacta.2013.07.057
M3 - Article
AN - SCOPUS:84881015709
SN - 0013-4686
VL - 109
SP - 39
EP - 45
JO - Electrochimica Acta
JF - Electrochimica Acta
ER -