【作者】 杨明；

【导师】 吴志明；

【作者基本信息】 电子科技大学 ， 光学工程， 2014， 硕士

【摘要】 钽酸锂(LiTaO3)是一种优秀的热释电材料,由其制作的太赫兹热释电探测器具有体积小、性价比高的优点,且其生产过程对周围环境不存在污染,使其成为军用、商用制备热释电探测器的热门材料。本论文是对基于LiTa O3的太赫兹热释电单元器件进行研究,采用新型的Sol-Gel法制备高性能的LiTaO3薄膜材料,测试了薄膜的介电、铁电、热释电性能,并应用软件对基于实验材料的探测器进行建模和仿真,为太赫兹热释电探测器以后的制备工作提供理论依据。论文主要的研究内容如下:采用新型的Sol-Gel方法制备了高浓度的LiTaO3胶体溶液。使用新型的高溶解度的1.2-丙二醇为实验的溶剂,制备浓度高达1.2 mol/L的LiTaO3溶液,大大减少了匀胶甩胶重复的次数,缩短实验的周期,提高了制备薄膜的效率。研究新型LiTaO3薄膜的制备工艺及其介电、漏电、热释电性能。在Pt和FTO导电薄膜电极上制备LiTaO3薄膜,并研究不同衬底材料、不同退火气氛及温度对LiTaO3薄膜结晶的影响;研究不同退火气氛对LiTaO3薄膜介电常数、介电损耗的影响;研究Pt与新型FTO导电薄膜为下电极的LiTaO3薄膜铁电及热释电的性能。实验中,10 kHz时Pt和新型FTO导电薄膜下电极上制备的LiTa O3薄膜的介电损耗分别为0.006和0.011,介电常数分别为45和54;两种衬底上薄膜漏电电流分别为4.67×10-8 A/cm2和5.12×10-7 A/cm2;在64℃时,其热释电系数值分别为1.43×10-8μC/(cm2·K)和1.22×10-8μC/(cm2·K);计算制备LiTaO3薄膜的电压响应优值和探测度优值,其值分别为0.99×10-10·C·cm·J-1和0.61×10-8·C·cm·J-1。本实验制备的材料与其它类型的热释电材料相比更有优势。应用IntelliSuite软件对基于LiTaO3薄膜的太赫兹热释电探测器的板凳型和锥型结构进行建模与仿真。并将锥型结构与传统的板凳型结构进行对比,研究不同尺寸的探测器和不同的接触面积对探测器结构的热学与力学的影响。证明锥型结构对于薄膜型探测器而言更可行。更多还原

【Abstract】 LiTaO3 is an excellent pyroelectric materials and is widely used in the preparation of pyroelectric detectors for military and commercial purposes, as the result of its small size, high cost performance, and no pollution in its production. This paper aims to research Terahertz Pyroelectric Unit Devices that are based on LiTaO3.The high performance LiTaO3 films made by Sol-gel are tested in the perspective of dielectric, pyroelectric, and ferroelectric performances. Then both modeling and simulation are realized with the help of detectors that are based on experimental materials. Therefore, this paper provides theory basis for subsequent preparation of Terahertz Pyroelectric Unit Devices. The main studies of this paper are as follows:A new way called Sol-Gel to prepare high concentrations of LiTaO3 colloidal solution is employed in the experiment. The author takes 1.2-propanediol that has high solubility as the solvent to prepare Li TaO3 solution, the concentration of which reaches 1.2 mol/L.This attributes to the great reduction of repetition of spinning and the experiment period. The production of films is also more efficient.Technology method of LiTa O3 films and its dielectric, leakage, and pyroelectric performances are studied. The study includes:(1) preparing LiTaO3 films on Pt and FTO substrates, the author discusses the influence of different substrates, different annealing situations to LiTaO3 films and to the dielectric constant and loss;(2) the author also does the research on ferroelectric and pyroelectric performances of LiTa O3 film on Pt and FTO substrates. In the experiment, the dielectric losses of LiTaO3 on Pt and FTO substrates are 0.006 and 0.011 at the frequency of 10 kHz. Under the same condition, the dielectric constants are 45 on Pt substrate and 54 on FTO substrate, at the same time their leakages are 4.67×10-8 A/cm2 and5.12×10-7 A/cm2;the pyroelectric coefficient are1.43×10-8 μC/(cm2·K) on Pt substrate and 1.22×10-8 μC/(cm2·K) on FTO substrate. As for voltage response of merit and detection merit, they are 0.99×10-10 C·cm·J-1 and 0.61×10-8 C·cm·J-1. This proves that LiTaO3 films are better than other pyroelectric materials.Intellisuite is employed to carry out bench type and cone modeling and simulation of Terahertz pyroelectric detectors. The detectors are based on LiTaO3 films. Compared with traditional bench type structure in the influence of size, contact area, cone structure performances better in film detectors.更多还原