硅、锗材料的电光效应和光整流效应的研究

发布时间：2018-01-21 00:30

本文关键词： IV族半导体材料硅基光电子学二阶非线性光学效应电光效应光整流效应载流子色散效应　出处：《吉林大学》2017年博士论文　论文类型：学位论文

【摘要】：硅和锗都是第一代半导体材料,在微电子学和光电子技术领域获得了重要应用。特别是硅材料,由于其价格低廉,工艺成熟,利于集成,在1.3μm和1.55μm通讯波段是透明的,因而在集成光学和光电子学领域广受青睐。近年来,由于锗材料与硅的CMOS工艺兼容性良好,且对中红外光具有良好的透过性,可将现有的通讯波长扩展至中红外波段,因此锗基光电器件在硅基光电子学中的应用也引起了人们的关注。所以,本论文重点开展了硅和锗材料表面层中的Pockels效应和光整流效应的研究工作,并将锗材料的Franz-Keldysh效应和载流子色散效应作为广义电光效应进行了理论研究。这些研究工作为拓展硅和锗材料在光电子学及非线性光学领域中的应用提供了实验和理论依据。论文的主要研究内容及取得的主要研究结果如下:(1)基于经典非线性极化理论,对硅和锗材料晶面表层中电场诱导的Pockels效应和光整流效应进行了理论分析。测量了Si(001)和Si(110)晶面表层中的Pockels信号和光整流信号。Pockels信号与外加调制电压呈良好的线性关系,比Kerr信号大得多;光整流信号随线偏振光的偏振方位角呈周期为π的余弦变化关系。这些实验结果与理论预期符合得很好。利用光整流信号随线偏振光偏振方位角变化的拟合函数,计算了Si(001)、Si(110)晶面表层中等效二阶极化率张量元的比值。(2)研究了Si(001)和Si(110)晶面表层中光整流信号沿晶面法线方向上的分布,证明光整流信号大小与硅表面性质是密切相关的。建立了光整流信号与表层中的自建电场及光波电场关系的理论模型,用自建电场与高斯光束光波电场的重叠积分解释了光整流信号的分布结果,理论模型与实验数据很好地符合。证明了利用光整流效应和Pockels效应研究硅晶面表层中自建电场强度与分布、空间电荷区宽度等表面性质的可行性。此外,还对Si(001)和Si(110)晶面表层的二阶非线性性质进行了比较。(3)首次研究了Ge(001)、Ge(110)晶面表层中电场诱导的光整流效应,测量了光整流信号随线偏振光偏振方位角的关系,以及光整流信号沿晶面法线方向上的分布。利用(2)中所述的理论模型也能很好地解释Ge(001)与Ge(110)晶面表层中光整流分布的实验结果。证明利用光整流效应研究晶面表层性质的方法对其它具有反演对称性的材料也适用。此外,还对Ge(111)晶面表层中电场诱导的Pockels效应和光整流效应进行了初步研究。(4)将锗的Franz-Keldysh效应和载流子色散效应作为广义电光效应进行了系统的理论研究。给出了不同波长下锗材料的吸收系数改变量、折射率改变量与电场强度,以及与载流子浓度改变量之间关系的理论公式。结果表明,载流子浓度的变化会引起锗材料的折射率的显著改变,因而载流子色散效应有望作为锗基光调制器的潜在工作机制。
[Abstract]:Silicon and germanium, both of the first generation semiconductor materials, have been widely used in the field of microelectronics and optoelectronic technology. It is transparent in 1.3 渭 m and 1.55 渭 m communication bands, so it is widely used in the field of integrated optics and optoelectronics. In recent years, germanium materials have good compatibility with silicon CMOS process. And has good transmission to the infrared light, can extend the existing communication wavelength to the mid-infrared band, so the application of germanium based optoelectronic devices in silicon-based optoelectronics has also attracted people's attention. In this thesis, the Pockels effect and optical rectification effect in the surface layer of silicon and germanium are studied. The Franz-Keldysh effect and carrier dispersion effect of germanium are studied theoretically as generalized electro-optic effects. These studies aim to expand the optoelectronics and nonlinear optics of silicon and germanium materials. The application in the field provides experimental and theoretical basis. The main research contents and the main results obtained are as follows:. (. 1) based on classical nonlinear polarization theory. The Pockels effect and optical rectification effect induced by electric field in the surface layer of silicon and germanium are theoretically analyzed. There is a good linear relationship between Pockels signal and optical rectifier signal. Pockels signal in the surface of crystal surface and the applied modulation voltage. The signal is much larger than the Kerr signal. The polarization azimuth of the optical rectifier signal varies with the polarization azimuth angle of the line polarized light. These experimental results are in good agreement with the theoretical expectation. The fitting function of the optical rectifier signal with the polarization azimuth angle of the line polarized light is obtained. . The Si-001) is calculated. The ratio of equivalent second-order polarizability Zhang Liang element in the surface layer of Si-110) and the distribution of optical rectifier signal along the normal direction of crystal plane are studied. It is proved that the size of the optical rectifier signal is closely related to the surface properties of silicon. The theoretical model of the relationship between the optical rectifier signal and the self-built electric field and the photowave electric field in the surface layer is established. The distribution of optical rectifier signal is explained by the overlap integral of self-built electric field and Gao Si beam light wave electric field. The theoretical model is in good agreement with the experimental data. It is proved that the intensity and distribution of self-built electric field in the surface layer of silicon crystal surface are studied by using optical rectification effect and Pockels effect. The feasibility of surface properties such as the width of space charge region. The second order nonlinear properties of the surface layer of Si-001) and Si-110) have been studied for the first time by comparing the second-order nonlinear properties of the surface layer of Si-001) and Si-110). The optical rectification effect induced by electric field in the surface layer of GE _ (110) crystal plane is measured. The relationship between the polarization azimuth of the optical rectifier signal and the polarization of the line polarized light is measured. And the distribution of optical rectifier signal along the normal direction of crystal plane. The experimental results of optical rectifying distribution in the surface layer of crystal plane prove that the method of using optical rectification effect to study the properties of surface layer of crystal plane is also suitable for other materials with inverse symmetry. The Pockels effect and optical rectification effect induced by electric field in the surface layer of Gei _ (111) are also studied. The Franz-Keldysh effect and carrier dispersion effect of germanium as generalized electro-optic effects are systematically studied. The change of absorption coefficient of germanium materials at different wavelengths is given. The theoretical formula of the relationship between refractive index change and electric field intensity and carrier concentration change. The results show that the change of carrier concentration can cause significant change of refractive index of germanium material. Therefore, carrier dispersion effect is expected to be the potential working mechanism of germanium based optical modulator.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN304

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