Theoretical studies on the electronic and optical properties of arene‐ versus fluoroarene‐thiophene co‐oligomer
Theoretical studies on the electronic and optical properties of arene‐ versus fluoroarene‐thiophene co‐oligomer
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DOI：
10.1002/poc.1499
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发表时间：
2009-07
影响因子：
1.8
通讯作者：
Xue-Qin Ran;Ji-Kang Feng;Aimin Ren;W. Tian;Luyi Zou;Yan-ling Liu;Chia-Chung Sun
中科院分区：
文献类型：
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作者：
Xue-Qin Ran;Ji-Kang Feng;Aimin Ren;W. Tian;Luyi Zou;Yan-ling Liu;Chia-Chung Sun
从理论上研究了一系列具有不同区域化学结构和核尺寸扩展的芳烃和氟芳烃-噻吩共低聚物以及未取代的六硫杂噻吩型α6T的电学和光学性质。这些苯并噻吩齐聚体由于可以通过各种结构调节来调节光学和电学性质，在有机发光二极管(OLED)、有机二极管激光器和有机薄膜晶体管(OTFT)中显示出巨大的应用潜力。用密度泛函理论(DFT)和从头算HF方法研究了低聚物基态的几何和电子结构，用单组态相互作用(CIS)方法研究了低聚物的最低单重态激发态。用含时密度泛函理论研究了低聚物的最低激发能、辐射寿命τ和最大吸收/发射波长。所有计算均使用6-31G(D)基组。结果表明，低聚物的HOMO、LumOS、能隙、电离势(IP)、电子亲合势(EAs)和重组能受到不同结构调谐的显著影响，这对改善OLED的空穴和电子注入具有重要意义。有趣的是，1b，2b和3b的LUMO能量比α6T和1a，2a，3a的低约0.12∼0.47 eV，表明氟苯基取代显著改善了低聚物的电子注入性能。版权所有©2008 John Wiley&Sons，Ltd.
A series of regiochemically varied and core size extension-modulated arene- and fluoroarene-thiophene co-oligomers and the unsubstituted sexithiophene α6T were investigated theoretically to explore their electronic and optical properties. These phenylene-thiophene oligomers show great potential for application in organic light-emitting diodes (OLEDs), organic diode lasers, and organic thin-film transistors (OTFTs) because of their feasible tuning of optical and electronic properties by the various structural tunings. Density functional theory (DFT) and the ab initio HF were employed to investigate the geometric and electronic structures of the oligomers in the ground state, and the singles configuration interaction (CIS) methods were used to study the lowest singlet excited state. The lowest excitation energies (Egs), the radiative lifetime τ, and the maximal absorption/emission wavelength of the oligomers were studied within time-dependent DFT (TDDFT). All calculations were performed using the 6-31G(d) basis set. The results show that the HOMOs, LUMOs, energy gaps, ionization potentials (IPs), electron affinities (EAs), and reorganization energies are significantly affected by the various structural tunings in these co-oligomers, which is important for the improvement of the hole and electron injection into OLEDs. Interestingly, the LUMO energy of 1b, 2b, and 3b is lower than that of α6T and 1a, 2a, 3a by about 0.12 ∼ 0.47 eV, indicating that the fluorophenyl-substitution has significantly improved the electron injection properties of the oligomers. Copyright © 2008 John Wiley & Sons, Ltd.