TY - JOUR
T1 - A visible-near-infrared absorbing A-π2-D-π1-D-π2-A type dimeric-porphyrin donor for high-performance organic solar cells
AU - Chen, Song
AU - Yan, Lei
AU - Xiao, Liangang
AU - Gao, Ke
AU - Tang, Wei
AU - Wang, Cheng
AU - Zhu, Chenhui
AU - Wang, Xingzhu
AU - Liu, Feng
AU - Peng, Xiaobin
AU - Wong, Wai-Kwok
AU - Zhu, Xunjin
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China (51473053 and 91333206), Hong Kong Research Grants Council (HKBU 22304115-ECS), Areas of Excellence Scheme ([AoE/P-03/08]), and Hong Kong Baptist University (FRG1/15-16/052 and FRG2/16-17/024). X. Zhu thanks The Science, Technology and Innovation Committee of Shenz-hen Municipality (JCYJ20150630164505504) for support. X. Z. Wang acknowledges the project of Innovation Platform Open Foundation of University of Hunan Province (14K092) and Hunan 2011 Collaborative Innovation Center of Chemical Engineering & Technology with Environmental Benignity and Effective Resource Utilization for the support. X. B. Peng acknowledges the International Science & Technology Cooperation Program of China (2013DFG52740) for support. Portions of this research were carried out at beamline 7.3.3 and 11.0.1.2 at the Advanced Light Source, Lawrence Berkeley National Laboratory, which was supported by the DOE, Office of Science, and Office of Basic Energy Sciences.
PY - 2017/12
Y1 - 2017/12
N2 - Most of the currently available small molecule bulk heterojunction organic solar cells (BHJ OSCs) only utilize visible light and, to further increase the efficiency, the development of new organic materials that harvest near-infrared (NIR) light to produce an electric current is essential. Herein, a new A-π2-D-π1-D-π2-A type dimeric porphyrin-cored small molecule (CS-DP) is designed, synthesized and characterized. The use of CS-DP with a narrow bandgap (Eg) (1.22 eV) and the deep energy levels of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) affords the highest power conversion efficiency of 8.29% in BHJ OSCs with PC71BM as an acceptor, corresponding to a short circuit current of 15.19 mA cm-2, an open circuit voltage of 0.796 V and a fill factor of 70% under AM 1.5G solar irradiation. The high device performance is attributed to the visible-near-infrared light-harvesting capability of CS-DP, and the super low energy loss feature. The energy loss (Eloss) lies between 0.43 and 0.51 eV in the system, which is related to the very small energy offset of the LUMOs between the CS-DP donor and PC71BM (ΔELUMO = 0.06 eV). The value of ΔELUMO, which is considered as a driving force for the photoinduced charge separation, is much smaller than the empirical threshold of 0.3 eV, but would not be a limiting factor in the charge separation process. The results indicate that there may be room for further improving the PCE for low bandgap dimeric porphyrin systems.
AB - Most of the currently available small molecule bulk heterojunction organic solar cells (BHJ OSCs) only utilize visible light and, to further increase the efficiency, the development of new organic materials that harvest near-infrared (NIR) light to produce an electric current is essential. Herein, a new A-π2-D-π1-D-π2-A type dimeric porphyrin-cored small molecule (CS-DP) is designed, synthesized and characterized. The use of CS-DP with a narrow bandgap (Eg) (1.22 eV) and the deep energy levels of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) affords the highest power conversion efficiency of 8.29% in BHJ OSCs with PC71BM as an acceptor, corresponding to a short circuit current of 15.19 mA cm-2, an open circuit voltage of 0.796 V and a fill factor of 70% under AM 1.5G solar irradiation. The high device performance is attributed to the visible-near-infrared light-harvesting capability of CS-DP, and the super low energy loss feature. The energy loss (Eloss) lies between 0.43 and 0.51 eV in the system, which is related to the very small energy offset of the LUMOs between the CS-DP donor and PC71BM (ΔELUMO = 0.06 eV). The value of ΔELUMO, which is considered as a driving force for the photoinduced charge separation, is much smaller than the empirical threshold of 0.3 eV, but would not be a limiting factor in the charge separation process. The results indicate that there may be room for further improving the PCE for low bandgap dimeric porphyrin systems.
UR - http://www.scopus.com/inward/record.url?scp=85038215738&partnerID=8YFLogxK
U2 - 10.1039/c7ta06217f
DO - 10.1039/c7ta06217f
M3 - Journal article
AN - SCOPUS:85038215738
SN - 2050-7488
VL - 5
SP - 25460
EP - 25468
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
IS - 48
ER -
