共查询到17条相似文献，搜索用时 62 毫秒
1.
吐昔烯衍生物的盘状液晶分子,在有机电子材料领域被用作光导材料和载流子传输材料。使用电子转移的Marcus模型,在B3LYP/6-31G**水平上研究了5个含三条烷氧链(n=1,3,5,8,10)的吐昔烯衍生物分子的电荷转移性质。计算表明,电荷转移矩阵元t是影响分子电荷转移的主要因素。5个分子中,随烷氧链长度(n)增大,空穴、电子传输重组能的变化范围分别为16~19 kJ/mol和26~ 30 kJ/mol。空穴传输矩阵元t+减小超过4倍,空穴传输载流子迁移率μ+减小超过3个数量级。电子传输矩阵元t-增大幅度不大,电子传输载流子迁移率μ-增大2倍,表明烷氧链增长不利于空穴传输,有利于电子传输。 相似文献
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使用密度泛函理论在B3LYP/6-31G**理论水平理论研究吐昔烯(TR)及含不同支链的7个衍生物分子的电荷传输性质。结果表明,吐昔烯及其7个衍生物的空穴传输速率常数在2.71×1012 s-1到1.80×1013 s-1之间,介于六氮杂苯并菲109 s-1和苯并菲1013 s-1之间。8个分子的电子传输速率常数位于1.16×1012 s-1到7.48×1012 s-1之间,大于苯并菲1011 s-1,小于六氮杂苯并菲1013 s-1。在吐昔烯刚性盘上引入羟基和烷氧基,没有改变空穴和电子传输速率常数的数量级。我们计算得到TR(OH)3(OC8H17)3和TR(OC5H11)3的空穴传输速率分别为9.74×10-2 cm2.v-1.s-1和3.78×10-1 cm2.v-1.s-1,与实验测得的两个化合物TR(OH)3(OC10H21)3和TR(OC8H17)3的空穴传输速率接近。 相似文献
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根据爱因斯坦方程和Marcus电荷传输模型, 使用密度泛函理论B3lyp/6-31g**理论水平计算6 个吐昔烯衍生物分子的结构和电荷传输性质. 结果显示: 6个吐昔烯的衍生物分子的空穴迁移速率为0.018–0.062 cm2·V-1·s-1, 电子迁移率为0.055–0.070 cm2·V-1·s-1, 其中3, 8, 13-辛烷氧基吐昔烯衍生物分子适合作为双极性传输材料. 三条烷氧基链的吐昔烯衍生物分子上引入三个甲氧基或羟基, 均使空穴和电子传输率降低. 引入给电子基团或共轭性基团可减小吐昔烯衍生物分子的能隙, 达到有机半导体的能隙要求.关键词：吐昔烯衍生物空穴传输电子传输有机半导体 相似文献
4.
采用含时密度泛函理论(TDDFT)B3LYP对5个吐昔烯及其衍生物分子的吸收光谱进行理论计算。结果表明,该5个分子的吸收波长在281—307 nm范围内,属于近紫外区。使用有限场(FF)方法理论计算5个化合物分子的非线性光学(NLO)性质。结果显示,吐昔烯分子引入烷氧基将明显增大二阶和三阶非线性光学性质（b0和 值）,此类化合物分子的三阶非线性光学性质明显优于二阶非线性光学性质。 相似文献
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六取代三环喹唑啉分子可以作为液晶半导体材料。使用电子传输的半经典模型和密度泛函理论方法在B3LYP/6-31G**水平上对六取代三环喹唑啉分子的电荷传输性质进行理论研究。结果显示,该分子的正电荷传输速率为负电荷传输速率的30倍。与苯并菲和六氮杂苯并菲比较,该分子更有利于正电荷传输。 相似文献
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基于电子转移的Marcus模型,以3,8,13-三丙烷氧基吐昔烯(a分子)为母体,采用密度泛函理论方法,在M062X/6-31+G(d)水平计算研究吐昔烯刚性核上的三个亚甲基被氮原子、氧原子、硫原子及羰基取代后所得的b、c、d、e等5个衍生物分子的结构和电荷传输性质.计算结果表明,b、d、e等3个吐昔烯衍生物分子的最低能量吸收峰均发生一定程度的红移(吸收波长在279-292 nm范围);掺杂氮原子、硫原子后,空穴传输载流子迁移率(μ_+)与电子传输载流子迁移率(μ_-)均明显增大,但μ_+比μ_-增加的幅度更大,更有利于空穴传输.掺杂氮原子,空穴迁移速率(μ_+)和电子迁移速率(μ_-)减小;掺杂羰基后,电子迁移速率(μ_-)增大,有利于电子传输,可设计为较好的电子传输材料. 相似文献
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采用含时密度泛函理论（TDDFT）B3LYP对5个吐昔烯及其衍生物分子的吸收光谱进行理论计算．结果表明,该5个分子的吸收波长在281～307nm范围内,属于近紫外区．使用有限场（FF）方法理论计算5个化合物分子的非线性光学（NLO）性质．结果显示,吐昔烯分子引入烷氧基将明显增大二阶和三阶非线性光学性质（β0和Y值）,此类化合物分子的三阶非线性光学性质明显优于二阶非线性光学性质． 相似文献
8.
在密度泛函理论B3LYP／6－31G**理论水平上,计算含乙酰胺基链苯并菲衍生物分子的电荷传输性质和热力学性质.研究结果显示,该分子的空穴传输性能明显好于电子传输性能.在298.15 K时,该分子的标准摩尔生成焓和生成自由能分别为－2338.79 kJ／mol和－1756.27 kJ／mol。 相似文献
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在密度泛函理论B3LYP/6-31G**理论水平上,计算含乙酰胺基链苯并菲衍生物分子的电荷传输性质和热力学性质。研究结果显示,该分子的空穴传输性能明显好于电子传输性能。在298.15 K时,该分子的标准摩尔生成焓和生成自由能分别为-2338.79 kJ/mol和-1756.27 kJ/mol。 相似文献
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11.
Takao Okazaki Gaku Aoyama Toshikazu Kitagawa 《Journal of Physical Organic Chemistry》2021,34(1):e4129
Reactions of 5‐R‐1‐indanones (R = Me, t‐Bu, Cl, F) in ionic liquids in the presence of Brønsted acid afforded substituted truxenes as aldol cyclotrimerization products, whose yields were found to be better in [BMIM][Tf2N] than in [BMIM][BF4]. Their cyclotrimerizations were slower and gave lower yields than that of the parent 1‐indanone. Furthermore, the reaction mixtures contained some amounts of intermediate products, 5‐R‐2‐(5‐R‐1‐indanylidene)‐1‐indanone, formed by the initial aldol condensation. These results suggested that both the electron‐donating and the electron‐withdrawing substituents at the C(5) position reduced the rate of cyclotrimerization. This rate retardation was supported by DFT/B3LYP calculations with the PCM solvation model. The activation energies of the reaction of the protonated indanones and the indenols in the initial aldol condensation were increased by both the electron‐donating group (EDG) and the electron‐withdrawing group (EWG). The transition states in the second aldol condensation and in the electron‐cyclization were also destabilized by both the EDG and the EWG. 相似文献
12.
六氮杂苯并菲及其衍生物电荷传输性质的理论研究 总被引：3，自引：0，他引：3
在B3LYP/6-31G**理论水平对六氮杂苯并菲及其衍生物和苯并菲及其衍生物分子及分子离子进行结构优化和频率计算,得到稳定构型.在此基础上,计算二聚物的单电能随旋转角度的变化关系,得到能量最低点.根据电子转移的半经典模型研究这些化合物分子的电荷传输性质.计算结果表明,六氮杂苯并菲的正电荷传输速率最小,负电荷传输速率最大.巯基,羟基,烷氧基和氟基团的取代有利于正电荷传输,不利于负电荷传输.烷氧基的链长对电荷传输性质几乎无影响.关键词：六氮杂苯并菲电荷传输盘状液晶 相似文献
13.
Muhammad Usman Khan Muhammad Yasir Mehboob Riaz Hussain Rafia Fatima Muhammad Suleman Tahir Muhammad Khalid Ataualpa Albert Carmo Braga 《Journal of Physical Organic Chemistry》2021,34(1)
End‐capped modification is a convenient strategy to enhance the photovoltaic and electronic properties of fullerene‐free acceptor materials. In this report, five novel star‐shaped three‐dimensional acceptor molecules FH1–FH5 are designed by end‐capped modifications of recently synthesized star‐shaped Tr (Hex)6‐3BR molecule. The enhancement in the photovoltaic, electronic, and photophysical properties of designed molecules is examined with the aid of density functional theory (DFT) and time‐dependent DFT (TDDFT). The MPW1PW91 functional in conjunction with 6‐31G(d,p) basis set of DFT/TDDFT is employed in order to compute various key parameters including frontier molecular orbitals analysis, absorption maxima, and binding energy along with transition density matrix, open‐circuit voltage, excitation energy, charge mobilities (electron and hole reorganizational energies), density of states, charge transfer with respect to HOMOPTB7‐Th–LUMOacceptor, and dipole moment. Red shifting in absorption spectra of acceptor materials is the most important reason for increasing efficiency of organic solar cells. A red shift in absorption spectra of all designed molecules is noted with low excitation energy. Designed molecules FH1–FH5 exhibit narrow energy gap with high electron mobility as compared with Tr (Hex)6‐3BR molecule. Among all designed molecules, FH4 is proved to be the best candidate for fullerene free organic solar cells because of narrow band gap, high charge mobility, high dipole moment, low excitation, and binding energy along with a red shift in absorption spectrum. Moreover, all designed molecules offer high current charge density as compared with Tr (Hex)6‐3BR. These results indicate that all star‐shaped conceptual molecules ( FH1–FH5 ) are ideal aspirants for construction of future organic solar cells. 相似文献
14.
有机半导体多层薄膜器件的性质很大程度上由有机-有机界面的传输性质所决定,但是现有的关于有机-有机界面的分析模型很难适用于实际器件的模拟.以Miller-Abrahams跳跃传导理论为基础,充分考虑有机-有机界面和金属-有机界面性质的不同,建立了一个新的描述有机-有机异质界面电荷传输的解析模型.结果表明有机异质界面的载流子传输不仅取决于界面的肖特基势垒,而且还取决于界面附近两边的电场强度和载流子浓度.此模型可用于有机半导体多层薄膜器件的电流密度、电场分布和载流子浓度分布的自洽计算.关键词：有机半导体界面载流子传输 相似文献
15.
A quantum mechanical approach has been used to investigate on the potential for using two naturally occurring flavonoids: quercetin and luteolin as candidates for organic semiconductor. Selection of flavonoids enables to evaluate the effects of hydroxyl group structural features. The relationship between molecular packing and charge transport in flavonoids is presented. The calculated results indicate that quercetin should be an ideal candidate as high-performance p-type organic semiconductor material, while luteolin is predicted as n-type organic semiconductor material. The predicted maximum electron mobility value of quercetin is 0.075 cm2 V?1 s?1, which appears at the orientation angle near 91°/271° of conducting channel on the reference planes b–c. Theoretical investigation of natural semiconductors is helpful for designing higher performance electronic materials used in biochemical and industrial field to replace expensive and rare organic materials. 相似文献
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在不同导电衬底(Au,Al和ITO)上制备了PTCDA薄膜,用XRD和AFM技术研究了PTCDA薄膜的结构和表面形貌。结果表明,薄膜中的大部分PTCDA分子平面与衬底不平行,这表明薄膜垂直方向的电流传导将以电子传输为主;在ITO和Au衬底上生长的PTCDA薄膜晶粒排列规则,在薄膜垂直方向呈现出较好的电子传输性能;而在Al衬底上生长的PTCDA薄膜晶粒排列无序,电子传输性能差。通过制备单层结构有机薄膜器件,研究了PTCDA薄膜垂直方向的电子迁移率。综合应用金属-有机界面的热电子发射理论和有机层体内空间电荷限制传导理论,并考虑电场强度对迁移率变化的影响,对ITO/PTCDA/Al器件的电流密度-电压曲线进行拟合,得到ITO衬底上生长的PTCDA薄膜在垂直方向随电场强度变化的电子迁移率数值。 相似文献
17.
《Advanced Optical Materials》2018,6(16)
The local optical anisotropy of 1D semiconductor nanorods (NRs), which results in anisotropic absorption and polarized emission, is important for various applications. Thin films of photoaligned, oriented NRs offer not only polarized emission but also anisotropic absorption at the macroscopic scale. Based on this anisotropic absorption, two kinds of optically addressable photoemissive displays are presented, which employ polarized backlight in combination with a liquid crystal (LC) based polarization rotator to control the down conversion emission intensity of a photoaligned NR/liquid crystal polymer (LCP) composite film. The first alternative “fixed information display” utilizes pattern aligned NRs, with an orthogonal easy axis in two domains, resulting in optical contrast in neighboring domains. The second option “random information display” employs unidirectionally aligned NR films as a projection screen to display any information coded by a LC cell. It is also shown that the NR/LCP composite film can align LC in bulk, and therefore, can be integrated into a LC cell, fabricating a robust photoemissive NR display device. 相似文献