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  本文關(guān)鍵詞： 聲學(xué)聲子 金屬納米線 量子化的聲子模式 電子-聲子相互作用　出處：《云南大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：納米科技對電子學(xué)、光電子學(xué)、材料科學(xué)等不同領(lǐng)域有著革命性的影響。納米結(jié)構(gòu)材料因在力、熱、光、電和磁等方面的特性,成為近幾十年來研究的熱點。目前已能制備各種金屬納米線結(jié)構(gòu)材料,其在光電子器件和超聲器件中具有重要的應(yīng)用價值。晶格振動的能量量子稱為聲子,量子化的聲子對納米結(jié)構(gòu)材料中的電子的輸運和熱傳導(dǎo)起著決定性的作用,材料的很多物理性質(zhì)受聲子模式以及電子聲子交互作用的影響,所以聲子一直是凝聚態(tài)物理學(xué)和電子學(xué)領(lǐng)域的重要研究對象。 本文主要研究了以氧化鋁為模板制備的金屬納米線結(jié)構(gòu)中的聲學(xué)聲子模式、電子子帶能級結(jié)構(gòu)、電子與聲子間的相互作用以及聲學(xué)聲子激發(fā)譜。改變金屬納米線的半徑、模板半徑,研究不同量子數(shù)m、v下的聲學(xué)聲子模式的變化,電子與聲子間的相互作用的強弱及聲子模式的激發(fā)譜特征；改變系統(tǒng)溫度,研究電子與聲子間的相互作用強弱及聲學(xué)聲子模式的激發(fā)譜特征。利用柱形納米線結(jié)構(gòu)來描述以氧化鋁為模板制備的金屬銅納米線�？紤]器件結(jié)構(gòu)中彈性聲波對應(yīng)的邊界及連續(xù)性條件,求解彈性波波動方程,可以得到金屬納米線結(jié)構(gòu)中的量子化聲學(xué)聲子模式。在此基礎(chǔ)上,我們研究了金屬納米線結(jié)構(gòu)中的電子-聲子相互作用及聲子激發(fā)譜。本文的研究內(nèi)容對金屬納米線系統(tǒng)在高頻超聲器件中的應(yīng)用有著重要的意義。 通過系統(tǒng)的理論研究,我們得出了一下結(jié)論： (1)聲子波矢較小時,金屬納米線結(jié)構(gòu)中不存在聲學(xué)聲子模式。當(dāng)聲子波矢增大到一定數(shù)值時,金屬納米線結(jié)構(gòu)中開始存在一系列不同的聲學(xué)聲子振動模式。 (2)金屬納米線結(jié)構(gòu)中的聲子波矢和聲子頻率近似為線性關(guān)系,且聲子頻率隨著聲子波矢的增大而增大。 (3)影響納米線結(jié)構(gòu)中的量子化聲子模式的主要因素為金屬納米線半徑r0,而納米線模板半徑不影響聲子的色散關(guān)系。 (4)金屬納米線結(jié)構(gòu)中的電子與聲子的交互作用主要受系統(tǒng)溫度、納米線半徑ro、電子態(tài)和聲子態(tài)的影響。 (5)金屬納米線結(jié)構(gòu)中的聲學(xué)聲子激發(fā)譜受系統(tǒng)溫度和納米線半徑的影響。系統(tǒng)溫度越高,通過電子-聲子交互作用引起的聲學(xué)聲子的激發(fā)越強,金屬納米線的半徑越小,聲學(xué)聲子的激發(fā)越強。
[Abstract]:Nanotechnology has revolutionized the fields of electronics, optoelectronics, material science, etc. Nanostructured materials are characterized by force, heat, light, electricity and magnetism. It has been widely used in photoelectron devices and ultrasonic devices. The energy quantum of lattice vibration is called phonon. Quantized phonons play a decisive role in the transport and heat conduction of electrons in nanostructured materials. Many of the physical properties of the materials are affected by phonon modes and electronic phonon interactions. Therefore, phonon has been an important research object in condensed matter physics and electronics. In this paper, the acoustic phonon mode, the energy level structure of electron subband, the interaction between electron and phonon, the excitation spectrum of acoustic phonon and the radius of metal nanowire are studied. Template radius, the variation of acoustic phonon modes at different quantum numbers mv, the intensity of the interaction between electrons and phonons and the characteristics of excitation spectrum of phonon modes, the change of system temperature, The intensity of interaction between electron and phonon and the excitation spectrum of acoustic phonon mode are studied. A columnar nanowire structure is used to describe the copper nanowires prepared by aluminum oxide template. The elastic acoustic pair in the device structure is considered. Boundary and continuity conditions, The quantized acoustic phonon modes in metal nanowire structures can be obtained by solving the wave equation of elastic waves. We have studied the electron-phonon interaction and phonon excitation spectra in metal nanowire structures. The research in this paper is of great significance to the application of metal nanowire systems in high-frequency ultrasonic devices. Through the systematic theoretical research, we draw a conclusion:. 1) when the phonon wave vector is small, there is no acoustic phonon mode in the metal nanowire structure. When the phonon wave vector increases to a certain value, there are a series of different acoustic phonon vibration modes in the metal nanowire structure. 2) the phonon wave vector and the phonon frequency in the metal nanowire structure are approximately linear, and the phonon frequency increases with the increase of the phonon wave vector. The main factor affecting the quantized phonon mode in nanowire structure is metal nanowire radius r _ 0, while the nanowire template radius does not affect the dispersion relationship of phonons. The interaction between electron and phonon in metal nanowire structure is mainly affected by system temperature, radius roof nanowire, electronic state and phonon state. 5) the acoustic phonon excitation spectrum in the metal nanowire structure is affected by the system temperature and nanowire radius. The higher the system temperature, the stronger the acoustic phonon excitation caused by electron-phonon interaction, and the smaller the metal nanowire radius. The stronger the acoustic phonon is.
【學(xué)位授予單位】：云南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TB383.1

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本文編號：1505282