Molecularly Smooth Single-Crystalline Films of Thiophene鈥揚henylene Co-Oligomers Grown at the Gas鈥揕iquid Interface
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- 作者：Valery A. Postnikov ; Yaroslav I. Odarchenko ; Alexander V. Iovlev ; Vladimir V. Bruevich ; Alexander Yu. Pereverzev ; Ludmila G. Kudryashova ; Vladimir V. Sobornov ; Lo茂c Vidal ; Dmitry Chernyshov ; Yuriy N. Luponosov ; Oleg V. Borshchev ; Nikolay M. Surin ; Sergei A. Ponomarenko ; Dimitri A. Ivanov ; Dmitry Yu. Paraschuk
- 刊名：Crystal Growth & Design
- 出版年：2014
- 出版时间：April 2, 2014
- 年：2014
- 卷：14
- 期：4
- 页码：1726-1737
- 全文大小：665K
- 年卷期：v.14,no.4(April 2, 2014)
- ISSN：1528-7505
文摘
Single crystals of thiophene鈥損henelyne co-oligomers (TPCOs) have previously shown their potential for organic optoelectronics. Here we report on solution growth of large-area thin single-crystalline films of TPCOs at the gas鈥搇iquid interface by using solvent鈥揳ntisolvent crystallization, isothermal slow solvent evaporation, and isochoric cooling. The studied co-oligomers contain identical conjugated core (5,5鈥?diphyenyl-2,2鈥?bithiophene) and different terminal substituents, fluorine, trimethylsilyl, or trifluoromethyl. The fabricated films are molecularly smooth over areas larger than 10 脳 10 渭m2, which is of high importance for organic field-effect devices. The low-defect structure of the TPCO crystals is suggested from the monoexponential kinetics of the PL decay measured in a wide dynamic range (up to four decades) and from low crystal mosaicity assessed by microfocus X-ray diffraction. The TPCO crystal structure is solved using a combination of X-ray and electron diffraction. The terminal substituents affect the crystal structure of TPCOs, bringing about the formation of a noncentrosymmetric crystal lattice with a crystal symmetry Cc for the bulkiest trimethylsilyl terminal groups, which is unusual for linear conjugated oligomers. Comparing the different crystal growth techniques, it is concluded that the solvent鈥揳ntisolvent crystallization is the most robust for fabrication of single-crystalline TPCOs films. The possible nucleation and crystallization mechanisms operating at the gas鈥搒olution interface are discussed.