本文關(guān)鍵詞：有機(jī)半導(dǎo)體的電子電離能、親和勢(shì)和極化能的密度泛函理論研究　出處：《華東師范大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

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【摘要】：近年來,由于具有輕便、可塑性好、制備方式靈活及生產(chǎn)成本低等優(yōu)點(diǎn),有機(jī)半導(dǎo)體材料受到了人們的廣泛關(guān)注,成為研究的熱點(diǎn)。為了設(shè)計(jì)新型有機(jī)半導(dǎo)體材料和理解相關(guān)機(jī)理,準(zhǔn)確預(yù)測(cè)有機(jī)半導(dǎo)體的能級(jí)(如電子電離能和親和勢(shì)等)具有重要意義。從理論計(jì)算的角度看,首要的挑戰(zhàn)來自于缺乏一種不僅能夠在定性上合理而且在定量上精確預(yù)測(cè),同時(shí)并不顯著增加計(jì)算成本的理論方法。本論文中,我們?yōu)榱藴?zhǔn)確預(yù)測(cè)有機(jī)半導(dǎo)體的能級(jí)參數(shù)率先提出了一種結(jié)合極化連續(xù)介質(zhì)模型(PCM)和"最優(yōu)調(diào)控"區(qū)間分離密度泛函的方法,并證明了該方法能夠準(zhǔn)確預(yù)測(cè)一系列有機(jī)半導(dǎo)體的電子電離能(IP),親和勢(shì)(EA)和極化能,其預(yù)測(cè)的結(jié)果能夠很好地重現(xiàn)實(shí)驗(yàn)數(shù)據(jù)。重要的是,經(jīng)過調(diào)控后分子的前線分子軌道能量(即-εHOMO和-εLUMO)與對(duì)應(yīng)的IP和EA計(jì)算值十分接近。調(diào)控方法的成功可以進(jìn)一步歸因于其能夠根據(jù)不同分子體系或同種分子所處的不同狀態(tài)(氣態(tài)和固態(tài))"最優(yōu)"地平衡泛函中分別用于描述電子局域化和離域化的作用。相比而言,其它常見的密度泛函方法由于包含的HF%比例過低(如PBE)或過高(如M06HF和未調(diào)控的區(qū)間分離泛函),均不能給予合理的預(yù)測(cè)。因此,我們相信這種PCM-調(diào)控的方法能夠?yàn)檠芯科渌訌?fù)雜的有機(jī)體系的能級(jí)問題提供一種更加可靠和便捷的理論工具。論文的主要內(nèi)容如下:第一章,綜述了理論計(jì)算的發(fā)展、有機(jī)半導(dǎo)體的概念、分類以及代表性有機(jī)薄膜器件。此外,通過分析實(shí)驗(yàn)研究中的不足說明采用理論計(jì)算預(yù)測(cè)有機(jī)半導(dǎo)體IP和EA的必要性;第二章,簡(jiǎn)單介紹了密度泛函理論的發(fā)展,包括Thomas-Fermi模型、Hohenberg-Kohn定理、Kohn-Sham方程以及在此基礎(chǔ)上發(fā)展出的各類密度泛函,繼而引出最優(yōu)調(diào)控密度泛函方法,并詳細(xì)闡述了該方法的理論基礎(chǔ)和發(fā)展過程;第三章,利用最優(yōu)調(diào)控密度泛函方法和其它9種常見的密度泛函方法對(duì)氣態(tài)和固態(tài)下分子的前線分子軌道能量(-εHOMO和-εLuMO)與IP和EA分別進(jìn)行計(jì)算,并與已有的實(shí)驗(yàn)值進(jìn)行比較,計(jì)算各參數(shù)理論計(jì)算值相對(duì)于實(shí)驗(yàn)值的平均絕對(duì)誤差(MAD)大小并進(jìn)行相應(yīng)的誤差分析。對(duì)比結(jié)果表明最優(yōu)調(diào)控方法能夠準(zhǔn)確地預(yù)測(cè)上述能級(jí)參數(shù)和極化能,而其它泛函計(jì)算結(jié)果則存在不同程度的誤差;第四章,總結(jié)了本論文的主要內(nèi)容,并對(duì)進(jìn)一步的研究做出展望。
[Abstract]:In recent years, organic semiconductor materials have attracted wide attention due to their advantages such as portability, good plasticity, flexible preparation and low production cost. In order to design new organic semiconductor materials and understand the related mechanism. It is important to accurately predict the energy levels of organic semiconductors (such as electron ionization energy and affinity potential). The primary challenge is the lack of a theoretical method that can not only be qualitatively reasonable but also quantitatively accurate, and does not significantly increase computational costs. In order to accurately predict the energy level parameters of organic semiconductors, we first proposed a method combining the polarization continuum model (PCM) and the "optimal regulation" region to separate the density functional. It is proved that this method can accurately predict the electron ionization energy (IP), affinity energy (EAA) and polarization energy of a series of organic semiconductors, and the predicted results can reproduce the experimental data well. Regulated frontier molecular orbital energy (i.e.-蔚 HOMO and-蔚 LUMOA). The success of the control method can be further attributed to its ability to operate in accordance with different molecular systems or different states of the same molecule (gaseous and solid). The "optimal" ground equilibrium Functionals are used to describe the effects of electron localization and delocalization, respectively. Other common density functional methods can not be reasonably predicted because the percentage of HF% included is too low (e.g. PBE) or too high (such as M06HF and unregulated interval separation functional). We believe that this PCM-regulation method can provide a more reliable and convenient theoretical tool for studying the energy level problems of other more complex organic systems. The main contents of this paper are as follows: chapter 1. The development of theoretical calculation, the concept, classification and representative organic thin film devices of organic semiconductors are reviewed. The necessity of predicting IP and EA of organic semiconductors by theoretical calculation is explained by analyzing the shortcomings of experimental research. In chapter 2, the development of density functional theory is briefly introduced, including the Hohenberg-Kohn theorem of Thomas-Fermi model. Kohn-Sham equation and all kinds of density functional developed on this basis, then the optimal control density functional method is derived, and the theoretical basis and development process of the method are described in detail. Chapter three. Using the optimal regulative density functional method and nine other common density functional methods, the orbital energies of frontier molecules in gaseous and solid state have been studied by means of 蔚 蔚 HOMO and 蔚 Lumo. Calculate with IP and EA separately. And compared with the existing experimental values. The mean absolute error between the calculated values of each parameter theory and the experimental values / mad). The comparison results show that the optimal control method can accurately predict the above energy level parameters and polarization energy. Other functional results have different degrees of error. Chapter 4th summarizes the main contents of this paper and makes a prospect for further research.
【學(xué)位授予單位】：華東師范大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O649.5;O641.1

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本文編號(hào)：1436648