TY - JOUR
T1 - Two new D-A conjugated polymers P(PTQD-Th) and P(PTQD-2Th) with same 9-(2-octyldodecyl)-8H-pyrrolo[3,4-b]bisthieno[2,3-f:3′,2′-h]quinoxaline-8,10(9H)-dione acceptor and different donor units for BHJ polymer solar cells application
AU - Keshtov, M. L.
AU - Kuklin, S. A.
AU - Chen, Fang-Chung
AU - Khokhlov, A. R.
AU - Peregudov, A. S.
AU - Siddiqui, S. A.
AU - Sharma, G. D.
PY - 2015/6/3
Y1 - 2015/6/3
N2 - We report the synthesis, characterization and photovoltaic properties of bulk heterojunction polymer solar cells of new donor-acceptor conjugated copolymers P(PTQD-Th) and P(PTQD-2Th) that incorporate same strong 9-(2-octyldodecyl)-8H-pyrrolo[3,4-b]bisthieno[2,3-f:3′,2′-h]quinoxaline-8,10(9H)-dione as strong acceptor and different weak thiophene (Th) and bi-thiophene (2Th) as donors, respectively. Both the copolymers showed suitable unoccupied lowest molecular orbital (LUMO) energy levels, compatible with the LUMO of PC71BM for efficient electron transfer from copolymer to PC71BM in the blended copolymer: PC71BM thin films. Moreover the deeper highest occupied molecular orbital (HOMO) energy levels of both copolymers ensures the high open circuit voltage (Voc) of the BHJ polymer solar cells. The optimized P(PTQD-Th):PC71BM and P(PTQD-2Th):PC71BM with weight ratio of 1:2 processed with chloroform solvent showed PCE of 3.65% and 3.96%, respectively. The higher value of Jsc for the device processed with P(PTQD-2Th):PC71BM as compared to that for P(PTQD-Th):PC71BM, attributed to narrower optical bandgap and broader absorption profile for P(PTQD-2Th) as compared to P(PTQD-Th). The PCE values of polymer solar cells were further improved (5.54% and 5.67% for P(PTQD-Th):PC71BM and P(PTQD-2Th):PC71BM, respectively) when small amounts of solvent additive, i.e. 1,8-diiodoctane (DIO) were used for the processing of active layers. The improved PCE has been attributed to both the enhanced values of short circuit current (Jsc) and fill factor (FF) due to the better nanomorphology and charge transport, induced by the high boiling point of solvent additive.
AB - We report the synthesis, characterization and photovoltaic properties of bulk heterojunction polymer solar cells of new donor-acceptor conjugated copolymers P(PTQD-Th) and P(PTQD-2Th) that incorporate same strong 9-(2-octyldodecyl)-8H-pyrrolo[3,4-b]bisthieno[2,3-f:3′,2′-h]quinoxaline-8,10(9H)-dione as strong acceptor and different weak thiophene (Th) and bi-thiophene (2Th) as donors, respectively. Both the copolymers showed suitable unoccupied lowest molecular orbital (LUMO) energy levels, compatible with the LUMO of PC71BM for efficient electron transfer from copolymer to PC71BM in the blended copolymer: PC71BM thin films. Moreover the deeper highest occupied molecular orbital (HOMO) energy levels of both copolymers ensures the high open circuit voltage (Voc) of the BHJ polymer solar cells. The optimized P(PTQD-Th):PC71BM and P(PTQD-2Th):PC71BM with weight ratio of 1:2 processed with chloroform solvent showed PCE of 3.65% and 3.96%, respectively. The higher value of Jsc for the device processed with P(PTQD-2Th):PC71BM as compared to that for P(PTQD-Th):PC71BM, attributed to narrower optical bandgap and broader absorption profile for P(PTQD-2Th) as compared to P(PTQD-Th). The PCE values of polymer solar cells were further improved (5.54% and 5.67% for P(PTQD-Th):PC71BM and P(PTQD-2Th):PC71BM, respectively) when small amounts of solvent additive, i.e. 1,8-diiodoctane (DIO) were used for the processing of active layers. The improved PCE has been attributed to both the enhanced values of short circuit current (Jsc) and fill factor (FF) due to the better nanomorphology and charge transport, induced by the high boiling point of solvent additive.
KW - Bulk heterojunction
KW - Polymer solar cells
KW - Power conversion efficiency
KW - Solvent additive
KW - Strong acceptor-weak donor D-A copolymer
UR - http://www.scopus.com/inward/record.url?scp=84930658227&partnerID=8YFLogxK
U2 - 10.1016/j.orgel.2015.05.023
DO - 10.1016/j.orgel.2015.05.023
M3 - Article
AN - SCOPUS:84930658227
VL - 24
SP - 137
EP - 146
JO - Organic Electronics: physics, materials, applications
JF - Organic Electronics: physics, materials, applications
SN - 1566-1199
ER -