第一性原理的形变势理论研究声学声子散射对电荷传输的影响 | |
唐令 ; 龙孟秋 ; 王冬 ; 帅志刚 ; TANG Ling ; LONG MengQiu ; WANG Dong ; SHUAI ZhiGang | |
2010-06-10 ; 2010-06-10 | |
关键词 | 迁移率 声学声子散射 玻尔兹曼方程 有机材料 mobility, acoustic phonon scattering, Boltzmann equation, organic materials O481 |
其他题名 | The role of acoustic phonon scattering in charge transport in organic semiconductors:a first-principles deformation-potential study |
中文摘要 | 本文应用密度泛函理论和玻尔兹曼方程,在形变势理论的框架和驰豫时间近似下,研究了分子晶体中电子与声学声子散射对电荷传输的影响.针对蒽、萘、丁省和并五苯的计算表明,非局域化电子的传输过程主要受到来自于声学声子的散射.对于蒽晶体,与以前的Holstein-Peierls模型计算结果相比,发现纵向声学声子对空穴的散射强度是光学声子的3倍,所得到的空穴迁移率更接近超纯单晶样品的实验测量结果.同时,我们发现电子的本征迁移率比空穴还要大,应用前线轨道交叠分析可以合理地解释这一结果.; The electron-acoustic phonon scattering for charge transport in organic semiconductors has been studiedby first-principles density functional theory and the Boltzmann transport equation with relaxation time approxima-tion. Within the framework of deformation-potential theory, the electron-longitudinal acoustic phonon scatteringprobability and the corresponding relaxation time have been obtained for oligoacene single crystals (naphthalene,anthracene, tetracene and pentacene). Previously, the electron-optic phonon scattering mechanism has been investi-gated through Holstein-Peierls model coupled with DFT calculations for naphthalene. Numerical results indicate thatthe acoustic phonon scattering intensity is about 3 times as large as that for the optic phonon and the obtained mobil-ity is in much better agreement with the result of the experiment done for ultrapure single crystals. It is thus con-cluded that for closely packed molecular crystal where the electron is partly delocalized, acoustic phonon scatteringmechanism prevails in the charge transport. Moreover, it is found that the intrinsic electron mobility is even largerthan hole mobility. A frontier orbital overlap analysis can well rationalize such behavior.; 国家重点基础研究发展计划(编号:2006CB806200,2006CB932100,2009CB623600); 国家自然科学基金(批准号:20833004)资助 |
语种 | 中文 ; 中文 |
内容类型 | 期刊论文 |
源URL | [http://hdl.handle.net/123456789/60931] ![]() |
专题 | 清华大学 |
推荐引用方式 GB/T 7714 | 唐令,龙孟秋,王冬,等. 第一性原理的形变势理论研究声学声子散射对电荷传输的影响[J],2010, 2010. |
APA | 唐令.,龙孟秋.,王冬.,帅志刚.,TANG Ling.,...&SHUAI ZhiGang.(2010).第一性原理的形变势理论研究声学声子散射对电荷传输的影响.. |
MLA | 唐令,et al."第一性原理的形变势理论研究声学声子散射对电荷传输的影响".(2010). |
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