TY - JOUR
T1 - Synthesis and characterization of indeno[1,2-b]fluorene-based low bandgap copolymers for photovoltaic cells
AU - Kim, Jinseck
AU - Kim, Sun Hee
AU - Jung, In Hwan
AU - Jeong, Eunjae
AU - Xia, Yangjun
AU - Cho, Shinuk
AU - Hwang, In Wook
AU - Lee, Kwanghee
AU - Suh, Hongsuk
AU - Shim, Hong Ku
AU - Woo, Han Young
PY - 2010
Y1 - 2010
N2 - Two types of indenofluorene-based low bandgap conjugated polymers, poly(6,6′,12,12′-tetraoctylindeno[1,2-b]fluorene-co-4, 7-bis(2-thienyl)-2,1,3-benzothiadiazole) (PIF-DBT) and poly(6,6′,12, 12′-tetraoctylindeno[1,2-b]fluorene-co-5,7-dithien-2-yl-thieno[3,4-b] pyrazine) (PIF-DTP), were synthesized and characterized for use in plastic solar cells. The optical, electrochemical, charge carrier mobility, morphological and photovoltaic characteristics were investigated. The number-average molecular weights of the polymers measured by gel permeation chromatography ranged from 19000 to 27000 g mol-1. The polymers were fairly soluble in common organic solvents and formed optical-quality films by spin casting. Photophysical studies revealed a low bandgap of ∼1.9 eV for PIF-DBT and ∼1.6 eV for PIF-DTP, respectively, which could harvest the broad solar spectrum covering from 300 nm to 650 nm (PIF-DBT), and from 300 nm to 800 nm (PIF-DTP) in film. An electrochemical study confirmed the desirable HOMO/LUMO levels of the copolymers, which enable efficient electron transfer and a high open circuit voltage when blending them with fullerene derivatives. The field effect mobility measurements showed a hole mobility of 10-5∼10-3 cm2 V-1 s-1 for the copolymers. The film surface morphology was also studied by atomic force microscopy. Among the polyindenofluorene copolymers, PIF-DBT50 (containing 50 mol% DBT) showed the best photovoltaic performance with an open circuit voltage of 0.77 V, a short circuit current of 5.50 mA cm-2 and a power conversion efficiency of 1.70% when the polymers were blended with PC71BM, under air mass 1.5 global (AM 1.5G, 100 mW cm-2) illumination conditions.
AB - Two types of indenofluorene-based low bandgap conjugated polymers, poly(6,6′,12,12′-tetraoctylindeno[1,2-b]fluorene-co-4, 7-bis(2-thienyl)-2,1,3-benzothiadiazole) (PIF-DBT) and poly(6,6′,12, 12′-tetraoctylindeno[1,2-b]fluorene-co-5,7-dithien-2-yl-thieno[3,4-b] pyrazine) (PIF-DTP), were synthesized and characterized for use in plastic solar cells. The optical, electrochemical, charge carrier mobility, morphological and photovoltaic characteristics were investigated. The number-average molecular weights of the polymers measured by gel permeation chromatography ranged from 19000 to 27000 g mol-1. The polymers were fairly soluble in common organic solvents and formed optical-quality films by spin casting. Photophysical studies revealed a low bandgap of ∼1.9 eV for PIF-DBT and ∼1.6 eV for PIF-DTP, respectively, which could harvest the broad solar spectrum covering from 300 nm to 650 nm (PIF-DBT), and from 300 nm to 800 nm (PIF-DTP) in film. An electrochemical study confirmed the desirable HOMO/LUMO levels of the copolymers, which enable efficient electron transfer and a high open circuit voltage when blending them with fullerene derivatives. The field effect mobility measurements showed a hole mobility of 10-5∼10-3 cm2 V-1 s-1 for the copolymers. The film surface morphology was also studied by atomic force microscopy. Among the polyindenofluorene copolymers, PIF-DBT50 (containing 50 mol% DBT) showed the best photovoltaic performance with an open circuit voltage of 0.77 V, a short circuit current of 5.50 mA cm-2 and a power conversion efficiency of 1.70% when the polymers were blended with PC71BM, under air mass 1.5 global (AM 1.5G, 100 mW cm-2) illumination conditions.
UR - http://www.scopus.com/inward/record.url?scp=76349098924&partnerID=8YFLogxK
U2 - 10.1039/b919033c
DO - 10.1039/b919033c
M3 - Article
AN - SCOPUS:76349098924
VL - 20
SP - 1577
EP - 1586
JO - Journal of Materials Chemistry
JF - Journal of Materials Chemistry
SN - 0959-9428
IS - 8
ER -