Structures, electronic states, photoluminescence, and carrier transport properties of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles

doi:10.1021/ja044628b

CORC > 化学研究所 > 中国科学院化学研究所

	Structures, electronic states, photoluminescence, and carrier transport properties of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles
	Yu, G ; Yin, SW ; Liu, YQ ; Chen, JS ; Xu, XJ ; Sun, XB ; Ma, DG ; Zhan, XW ; Peng, Q ; Shuai, ZG
刊名	JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
	2005-05-04
卷号	127 期号:17 页码:6335-6346
ISSN号	0002-7863
DOI	10.1021/ja044628b
英文摘要	The excellent electroluminescent (EL) properties of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles, 1-methyl-1,2,3,4,5-pentaphenylsilole (MPPS), and 1,1,2,3,4,5-hexaphenylsilole (HPS) have been found. Despite some studies devoted to these materials, very little is known about the real origin of their unique EL properties. Therefore, we investigated the structures, photoluminescence (PL), and charge carrier transport properties of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles as well as the effect of substituents on these characteristics. The single crystals of the three siloles involving 1,1-dimethyl-2,3,4,5-tetraphenylsilole (DMTPS), MPPS, and HIPS were grown and their crystal structures were determined by X-ray diffraction. Three siloles have nonplanar molecular structures. The substituents at 1,1-positions enhance the steric hindrance and have predominant influence on the twisted degree of phenyl groups at ring carbons. This nonplanar structure reduces the intermolecular interaction and the likelihood of excimer formation, and increases PL efficiency in the solid state. The silole films show high fluorescence quantum yields (75-85%), whereas their dilute solutions exhibit a faint emission. The electronic structures of the three siloles were investigated using quantum chemical calculations. The highest occupied molecular orbitals (HOMOs) and the lowest unoccupied molecular orbitals (LUMOs) are mainly localized on the silole ring and two phenyl groups at 2,5-positions in all cases, while the LUMOs have a significant orbital density at two exocyclic Si-C bonds. The extremely theoretical studies of luminescent properties were carried out. We calculated the nonradiative decay rate of the first excited state as well as the radiative one. It is found that the faint emission of DMTPS in solutions mainly results from the huge nonradiative decay rate. In solid states, molecular packing can remarkably restrict the intramolecular rotation of the peripheral side phenyl ring, which has a large contribution to the nonradiative transition process. This explains why the 1,1-disubstituted 2,3,4,5-tetraphenylsiloles in the thin films exhibit high fluorescence quantum yields. The charge carrier mobilities of the MPPS and HPS films were measured using a transient EL technique. We obtained a mobility of 2.1 x 10(-6) cm(2)/V(.)s in the MPPS film at an electric field of 1.2 x 10(6) V/cm. This mobility is comparable to that of Alq(3), which is one of the most extensively used electron transport materials in organic light-emitting diodes (LEDs), at the same electric field. The electron mobility of the HPS film is about similar to 1.5 times higher than that of the MPPS film. To the best of our knowledge, this kind of material is one of the most excellent emissive materials that possess both high charge carrier mobility and high PL efficiency in the solid states simultaneously. The excellent EL performances of MPPS and HPS are presumably ascribed to these characteristics.
语种	英语
出版者	AMER CHEMICAL SOC
WOS记录号	WOS:000228755300045
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/57285]
专题	中国科学院化学研究所
通讯作者	Yu, G
作者单位	1.Chinese Acad Sci, Inst Chem, Organ Solids Lab, Beijing 100080, Peoples R China 2.Chinese Acad Sci, Changchun Inst Appl Chem, Key State Lab Polymer Phys & Chem, Changchun 130022, Peoples R China 3.Hong Kong Univ Sci & Technol, Dept Chem, Kowloon, Hong Kong, Peoples R China 4.Beijing Normal Univ, Dept Chem, Beijing 100875, Peoples R China 5.Royal Inst Technol, S-10691 Stockholm, Sweden
推荐引用方式 GB/T 7714	Yu, G,Yin, SW,Liu, YQ,et al. Structures, electronic states, photoluminescence, and carrier transport properties of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles[J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,2005,127(17):6335-6346.
APA	Yu, G.,Yin, SW.,Liu, YQ.,Chen, JS.,Xu, XJ.,...&Luo, Y.(2005).Structures, electronic states, photoluminescence, and carrier transport properties of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles.JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,127(17),6335-6346.
MLA	Yu, G,et al."Structures, electronic states, photoluminescence, and carrier transport properties of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles".JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 127.17(2005):6335-6346.