Steric minimization towards high planarity and molecular weight for aggregation and photovoltaic studies

CORC > 青岛生物能源与过程研究所 > 中国科学院青岛生物能源与过程研究所 > 先进有机功能材料团队

	Steric minimization towards high planarity and molecular weight for aggregation and photovoltaic studies
	Han, Liangliang 1; Hu, Tong 2; Bao, Xichang 1; Qiu, Meng 1; Shen, Wenfei 1; Sun, Mingliang 2; Chen, Weichao 1; Yang, Renqiang 1,3
刊名	JOURNAL OF MATERIALS CHEMISTRY A
	2015
卷号	3 期号:46 页码:23587-23596
英文摘要	Taking into account the effect of planarity, alkyl chain steric hindrance and molecular weight towards high performance polymer solar cells, a planar semiconducting polymer PTOBDTDTffBT is designed. Minimal intra- and inter-molecular steric hindrances are realized by removing the alkyl chains at the 4,4'-positions of the DTffBT monomer and introducing shorter octyloxy chains on the BDT unit, respectively. Such a steric minimization strategy endows PTOBDTDTffBT with a high number average molecular weight of 343.37 kg mol(-1), a planar conjugated backbone and strong inter-molecular aggregation characteristics as well. The optical properties indicate that the aggregation can only be partially broken even at 160 C; theoretical calculations indicate that the polymer backbone has small distortion and the thiophene-phenyl bridge can move the octyloxy chains outward by 6.77 A from the polymer backbone, both of which ensure the strong inter-chain aggregation. In spite of the high planarity and strong aggregation of the polymer, PTOBDTDTffBT is relatively amorphous in its film form, indicated by grazing incidence X-ray diffraction analysis. PTOBDTDTffBT exhibits a narrow bandgap of 1.71 eV together with a high ionization potential of 5.46 eV. Because of the strong aggregation of the polymer, the PTOBDTDTffBT/PC71BM active layer exhibits temperature-dependent photovoltaic performance. When the active layer is spin-coated at a relatively low temperature below 100 degrees C, PTOBDTDTffBT/PC71BM exhibits a stable power conversion efficiency above 6.6%. However, when the temperature is elevated from 120 degrees C to 160 degrees C, the power conversion efficiency decreased gradually to 3.58% because of the decreased short-circuit current density and fill factor. The temperature-dependent photovoltaic performance is explained by the fact that the PC71BM is easily spun out from the solution at higher temperatures as confirmed by the UV-vis absorption and X-ray photoelectron spectroscopy analysis. High temperatures can also lead to coarse morphology and large phase separation in the active layer observed from the atomic force microscopy and transmission electron microscopy images. Finally, a maximum power conversion efficiency of 7.68% is obtained when the active layer is spin-coated at 80 degrees C, which is a significant improvement of the power conversion efficiency for the planar PBDTDTffBT series.
WOS标题词	Science & Technology ; Physical Sciences ; Technology
类目[WOS]	Chemistry, Physical ; Energy & Fuels ; Materials Science, Multidisciplinary
研究领域[WOS]	Chemistry ; Energy & Fuels ; Materials Science
关键词[WOS]	POLYMER SOLAR-CELLS ; LOW-BANDGAP POLYMER ; CONJUGATED POLYMERS ; HIGH-PERFORMANCE ; FLUORINATED BENZOTHIADIAZOLE ; INTERCHAIN AGGREGATION ; DEVICE PERFORMANCES ; MORPHOLOGY ; EFFICIENCY ; POLY(3-HEXYLTHIOPHENE)
收录类别	SCI
语种	英语
WOS记录号	WOS:000365216000060
公开日期	2016-02-26
内容类型	期刊论文
源URL	[http://ir.qibebt.ac.cn/handle/337004/6796]
专题	青岛生物能源与过程研究所_先进有机功能材料团队
作者单位	1.Chinese Acad Sci, Key Lab Biobased Mat, Qingdao Inst Bioenergy & Bioproc Technol, Qingdao 266101, Peoples R China 2.Ocean Univ China, Inst Mat Sci & Engn, Qingdao 266100, Peoples R China 3.S China Univ Technol, State Key Lab Luminescent Mat & Devices, Guangzhou 510641, Guangdong, Peoples R China
推荐引用方式 GB/T 7714	Han, Liangliang,Hu, Tong,Bao, Xichang,et al. Steric minimization towards high planarity and molecular weight for aggregation and photovoltaic studies[J]. JOURNAL OF MATERIALS CHEMISTRY A,2015,3(46):23587-23596.
APA	Han, Liangliang.,Hu, Tong.,Bao, Xichang.,Qiu, Meng.,Shen, Wenfei.,...&Yang, Renqiang.(2015).Steric minimization towards high planarity and molecular weight for aggregation and photovoltaic studies.JOURNAL OF MATERIALS CHEMISTRY A,3(46),23587-23596.
MLA	Han, Liangliang,et al."Steric minimization towards high planarity and molecular weight for aggregation and photovoltaic studies".JOURNAL OF MATERIALS CHEMISTRY A 3.46(2015):23587-23596.