【作者】 裴子栋；

【导师】 孔勇发；

【作者基本信息】 南开大学 ， 光学， 2013， 博士

【摘要】 和集成电路相比,集成光路拥有着高速度、大容量和低损耗等特点。从集成光路的材料结构上看,单片型集成光路是人们所期望的。在实现相同功能时,单片型集成光路往往比混合型集成光路占据的体积更小,而且单片型集成光路制备起来更加容易,各种器件之间更加协调稳定。为了获得单片型集成光路,必须要有一种多功能的光学材料,而铌酸锂晶体正是这样的材料。铌酸锂晶体具有相当优异的光学和电学方面的性能,集电光、声光、热电、压电、光折变和非线性等效应于一身,可以制备出集成光路所需要的各种器件,如光波导、光开关、电光调制器、声光调制器、热电传感器、压电传感器、光参量振荡器、波分复用器和耦合器等等。为了制备出铌酸锂单片型集成光路,还缺少铌酸锂材料制备的激光器。我们知道pn结是一个半导体激光器的主要工作结构,因此,本论文的终极目标是制备出铌酸锂pn结,而且由于铌酸锂的禁带很宽,pn结发光的波长将位于紫外波段,这会对紫外激光二极管的发展提供一个新的途径。本论文的主要工作：我们以铌酸锂为主要材料的单片型或者是准单片型集成光路为目标。对于铌酸锂单片型集成光路,我们通过对铌酸锂载流子的调控寻找到了铌酸锂的p型材料,并通过各种镀膜技术生长了铌酸锂的同质pn结,pn结的I-V曲线测量显示出了良好的整流性能。考虑到铌酸锂晶体的导电性极差,我们又考虑了铌酸锂准单片型集成光路。在此集成光路中,高掺铁铌酸锂晶体显示出较好的导电性能,相比于不掺杂的同成分铌酸锂晶体,电导率可提高6个数量级,将高掺铁的铌酸锂晶体作为n型材料用激光分子束外延的方法将之生长到p型硅上,从而形成了铌酸锂/硅的异质pn结,此pn结也显示出了良好的整流性能。论文内容的安排如下：第一章,介绍了铌酸锂晶体的发展概况、结构特征、缺陷类型和占位、能带特征、载流子类型,以及集成光学的发展、特点和集成光路器件,简介了论文的主要目的和实验安排。第二章,介绍了导电类型检测方法,从中选出了最适合铌酸锂晶体的全息法；p型铌酸锂的制备,最终确定了3m01%掺锆铌酸锂晶体和热电氧化法处理的掺铁铌酸锂晶体具有p型的导电类型。第三章,分别用磁控溅射法、液相外延法和激光分子束外延法制备出了铌酸锂的同质结,并测量了这些同质结的伏安特性。第四章,高电导率铌酸锂的探寻,制备了导电性能大幅提高的高掺铁铌酸锂晶体；用激光分子束外延法制备出了铌酸锂/硅的异质结；对铌酸锂pn结的整流性能进行了测试。第五章,总结和展望,对本论文的工作进行总结,对今后的工作进行了展望。更多还原

【Abstract】 Compared with electronic integrated circuits, photonic integrated circuits (PICs) exhibit higher speed, larger capacity, lower propagation loss, etc. From the point of view of material structure, monolithic PICs are more expected. Monolithic PICs are often smaller than hybrid PICs to achieve the same function and furthermore fabrication of monolithic PICs is much easier, various devices in monolithic PICs are much more harmonious and steady. In order to obtain monolithic PICs, a multifunctional optical material is essential. Fortunately, lithium niobate (LiNbO3) is such a material.LiNbO3has excellent optical and electrical properties, such as electro-optic effect, acousto-optic effect, pyroelectric effect, piezoelectric effect, photorefractive effect, nonlinear effect, etc. Most devices used in PICs can be prepared by LiNbO3crystal, such as optical waveguide, optical switch, electro-optical modulator, acousto-optic modulator, pyroelectric sensor, piezoelectric sensor, optical parametric oscillator, wavelength division multiplexer, coupler, etc. To fabricate monolithic PICs, the main obstacle is a lack of laser diode (LD) based on LiNbO3wafer.As we known that pn junction is the main structure of a semiconductor diode, so the main purpose of this thesis is to fabricate LiNbO3pn junction. Because of its wide energy gap, LiNbO3pn junction will emit an ultraviolet light. This is helpful for LD luminescence.The main work of this dissertation can be decided to LiNbO3monolithic PICs and quasi-monolithic PICs. For the monolithic PICs, we try to fabricate p type LiNbO3by various dopants and oxidation, then grow the pn junctions by magnetron sputtering method, liquid phase epitaxial method and laser molecular beam epitaxial method. The pn junction shows good rectifying properties by measuring the current-voltage curve. Considering of the poor conductivity of LiNbO3crystal, we consider the quasi-monolithic PICs. Highly iron doped LiNbO3crystals show excellent conductive properties. Compared to the undoped congruent LiNbO3crystals, the conductivity can be improved by6orders of magnitude. We grow n-type high iron doped LiNbO3films on p-type silicon by laser molecular beam epitaxial method to form pn junctions. The pn junctions also show good rectifying properties.The content of this dissertation is arranged as follows:Chapter1introduces the development of LiNbO3, crystal structure, defect types and site occupation, energy band structure, carrier type, the development of integrated optics and integrated optical devices; we also give the main purpose of this thesis and experimental arrangement.Chapter2introduces the detection methods of conductive type. We find the holographic method is most suitable for LiNbO3crystal. Then we investigate p-type LiNbO3and finally find that3mol%zirconium doped LiNbO3crystal and iron doped LiNbO3crystals treated by thermo-electric oxidization are p-type ones.Chapter3, LiNbO3pn homojunctions are prepared by liquid phase epitaxy, magnetron sputtering and laser molecular beam epitaxy. Then the basic characteristics of these pn junctions are measured.Chapter4, we search for LiNbO3crystals with high conductivity. We grow highly iron doped LiNbO3crystals, its conductivity is6orders of magnitude than that of nominally pure one. Then we fabricate LiNbO3/Si heterojunction by laser molecular beam epitaxy. Properties of the pn junctions are investigated.Chapter5, summary and prospect, we summarize the work of this dissertation and prospect the futher work.更多还原