High-performance organic materials for dye-sensitized solar cells: triarylene-linked dyads with a 4-tert-butylphenylamine donor.
A series of organic dyes were prepared that displayed remarkable solar-to-energy conversion efficiencies in dye-sensitized solar cells (DSSCs). These dyes are composed of a 4-tert-butylphenylamine donor group (D), a cyanoacrylic-acid acceptor group (A), and a phenylene-thiophene-phenylene (PSP) spacer group, forming a D-π-A system. A dye containing a bulky tert-butylphenylene-substituted carbazole (CB) donor group showed the highest performance, with an overall conversion efficiency of 6.70%. The performance of the device was correlated to the structural features of the donor groups; that is, the presence of a tert-butyl group can not only enhance the electron-donating ability of the donor, but can also suppress intermolecular aggregation. A typical device made with the CB-PSP dye afforded a maximum photon-to-current conversion efficiency (IPCE) of 80% in the region 400-480 nm, a short-circuit photocurrent density J(sc) =14.63 mA cm(-2), an open-circuit photovoltage V(oc) =0.685 V, and a fill factor FF=0.67. When chenodeoxycholic acid (CDCA) was used as a co-absorbent, the open-circuit voltage of CB-PSP was elevated significantly, yet the overall performance decreased by 16-18%. This result indicated that the presence of 4-tert-butylphenyl substituents can effectively inhibit self-aggregation, even without CDCA.
Department of Chemistry, National Taiwan University, Taipei 106, Taiwan.
Yuan Jay
YJ
Chang
Po-Ting
PT
Chou
Szu-Yu
SY
Lin
Motonori
M
Watanabe
Zhi-Qian
ZQ
Liu
Ju-Ling
JL
Lin
Kew-Yu
KY
Chen
Shih-Sheng
SS
Sun
Ching-Yang
CY
Liu
Tahsin J
TJ
Chow
D000814:Aniline Compounds / Q000737:chemistry*; D004396:Coloring Agents / Q000138:chemical synthesis / Q000737:chemistry*; D011211:Electric Power Supplies; D015394:Molecular Structure; D011789:Quantum Theory; D012993:Solar Energy
C572788:4-tert-butylphenylamine; D000814:Aniline Compounds; D004396:Coloring Agents