几种有机半导体分子载流子迁移特性的研究
发布时间：2018-10-19 12:11
【摘要】：由于有机半导体材料受分子间弱相互作用的影响,载流子的跃迁速率相对较低。针对这一特点,本文基于Marcus跳跃模型对低聚噻吩衍生物、双并四苯衍生物以及Naphthalenediimide (NDTI)衍生物的载流子输运特性、迁移率进行了研究。得到如下结论：2,5-二(噻吩-2-基)噻吩[3,2-b]噻吩(T-T2-T)迁移率相对较大,可以达到0.226 cm2V-1s-1;分子有效共轭长度对重组能、相邻分子间耦合作用以及载流子迁移率产生影响。双并四苯衍生物较高的迁移率主要得益于较小的重组能和较大的相邻分子间有效耦合。长碳链的引入对重组能的大小几乎无影响。但长碳链的引入会导致分子间相对密集的堆积。这种密集的堆积方式可能会促进分子间的相互耦合作用,减小载流子在相邻分子间的有效扩散,从而导致迁移率的降低。基于对C8-NDTI迁移率的研究,通过对其简谐振动模式和键长弛豫分析,讨论了各化学元素对重组能的影响。发现：O元素会降低空穴转移过程中的重组能,同时增加相邻分子间的有效耦合,这有利于提高载流子迁移率。
[Abstract]:Due to the weak intermolecular interaction, the carrier transition rate is relatively low. In this paper, the carrier transport characteristics and mobility of thiophene derivatives, bis-tetraphenyl derivatives and Naphthalenediimide (NDTI) derivatives are studied based on Marcus hopping model. The results are as follows: the mobility of 2o 5- (thiophene 2-yl) thiophene [3H 2-b] thiophene (T-T2-T) is relatively large, and the effective conjugation length of 0.226 cm2V-1s-1; can influence the recombination energy, the coupling between adjacent molecules and the carrier mobility. The higher mobility of bis-tetraphenyl derivatives is mainly due to the smaller recombination energy and the larger effective coupling between adjacent molecules. The introduction of long carbon chains has little effect on the size of recombination energy. However, the introduction of long carbon chains will lead to a relatively dense accumulation of molecules. This dense stacking pattern may promote the interaction between molecules and reduce the effective diffusion of carriers between adjacent molecules, resulting in a decrease in mobility. Based on the study of the mobility of C8-NDTI, the influence of each chemical element on the recombination energy is discussed through the analysis of the simple harmonic vibration mode and bond length relaxation. It is found that O can decrease the recombination energy in the hole transfer process and increase the effective coupling between adjacent molecules, which is beneficial to increase the carrier mobility.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN304
本文编号：2281073
[Abstract]:Due to the weak intermolecular interaction, the carrier transition rate is relatively low. In this paper, the carrier transport characteristics and mobility of thiophene derivatives, bis-tetraphenyl derivatives and Naphthalenediimide (NDTI) derivatives are studied based on Marcus hopping model. The results are as follows: the mobility of 2o 5- (thiophene 2-yl) thiophene [3H 2-b] thiophene (T-T2-T) is relatively large, and the effective conjugation length of 0.226 cm2V-1s-1; can influence the recombination energy, the coupling between adjacent molecules and the carrier mobility. The higher mobility of bis-tetraphenyl derivatives is mainly due to the smaller recombination energy and the larger effective coupling between adjacent molecules. The introduction of long carbon chains has little effect on the size of recombination energy. However, the introduction of long carbon chains will lead to a relatively dense accumulation of molecules. This dense stacking pattern may promote the interaction between molecules and reduce the effective diffusion of carriers between adjacent molecules, resulting in a decrease in mobility. Based on the study of the mobility of C8-NDTI, the influence of each chemical element on the recombination energy is discussed through the analysis of the simple harmonic vibration mode and bond length relaxation. It is found that O can decrease the recombination energy in the hole transfer process and increase the effective coupling between adjacent molecules, which is beneficial to increase the carrier mobility.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN304
【参考文献】
相关期刊论文 前1条
1 陈海明;靳宝善;;有机半导体器件的现状及发展趋势[J];微纳电子技术;2010年08期
，本文编号：2281073
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