钽铌酸钾薄膜的结构与光学性能研究

发布时间：2018-05-06 21:49

本文选题：第一性原理 + 脉冲激光沉积　；参考：《哈尔滨理工大学》2016年硕士论文

【摘要】：近年来,薄膜制造技术的发展,极大推动了电光功能材料薄膜在光全息储存、光信息相位共轭、电光开关以及微电子集成等应用领域的研究。钽铌酸钾(KTaxNb1-xO3,KTN)晶体具有经典ABO3钙钛矿结构,因优良的二次电光性能和铁电性能是优秀的电光信息功能材料之一。本文研究了Ta/Nb为1:1的钽铌酸钾材料,利用基于密度泛函理论的第一性原理方法研究了有序KTN的结构与弹性性能,钾氧空位KTN的结构及光学性能,有序及Li原子掺杂KTN(KLTN)薄膜的结构及光学性能;运用脉冲激光沉积(Pulsed Laser Deposition,简称PLD)法在Pt和石英衬底上制备了择优取向度高的KTN薄膜,并利用双光束紫外可见分光光度计、椭偏仪研究了KTN薄膜的吸收、透射和折射等光学特性。首先,在Material Studio软件平台上构建了有序KTN晶体、钾氧空位KTN晶体、有序KTN薄膜以及Li原子掺杂KTN薄膜模型,然后运用局域态密度近似(LDA)研究计算了它们的结构、弹性、光学等物理性质,讨论有序结构及缺陷结构对材料性能的影响,并探究了(100)晶向的KTN和KLTN薄膜的光学性能。利用脉冲激光沉积法在Pt衬底上制备了(100)晶向上择优取向高达94.62%高品质KTN薄膜,运用双光束紫外可见分光光度计实现对薄膜的吸收和透射光谱曲线测量,发现KTN薄膜的吸收边在300 nm附近,在320~900 nm波长范围内透射率高达80%,利用椭偏仪对薄膜折射率等光学性质进行了测试与分析,得出KTN薄膜在可见光和近红外光波段的折射率n和消光系数k随着波长的增大而减小,符合正常色散Cauchy模型。
[Abstract]:In recent years, the development of thin film manufacturing technology has greatly promoted the research of electro-optic functional material films in the fields of optical holographic storage, optical information phase conjugation, electro-optic switch and microelectronic integration. Potassium tantalum niobate KTaxNb1-xO3 (KTNN) crystal has a classical ABO3 perovskite structure and is one of the excellent electro-optic information functional materials due to its excellent secondary electro-optic and ferroelectric properties. In this paper, Ta/Nb 1:1 potassium tantalum niobate materials are studied. The structure and elastic properties of ordered KTN, the structure and optical properties of KTN with potassium oxygen vacancy are studied by using the first-principle method based on density functional theory. The structure and optical properties of ordered and Li doped KTNN KLN thin films were studied. High preferred KTN thin films were prepared on Pt and quartz substrates by pulsed laser deposition, and double beam UV-Vis spectrophotometer was used. The absorption, transmission and refraction of KTN thin films have been studied by ellipsometry. First of all, an ordered KTN crystal, a KTN crystal with potassium oxygen vacancy, an ordered KTN film and a Li atom doped KTN thin film model are constructed on the Material Studio software platform. Then the structure and elasticity of these crystals are studied by using the local density of states approximation (LDAA). The effects of ordered structure and defect structure on the properties of KTN and KLTN thin films with crystal orientation are discussed. High quality KTN thin films with preferential orientation up to 94.62% were prepared on Pt substrates by pulsed laser deposition. The absorption and transmission spectra of the films were measured by dual-beam UV-Vis spectrophotometer. It is found that the absorption edge of KTN thin film is near 300nm and the transmittance is as high as 80 in the wavelength range of 320,900 nm. The optical properties such as refractive index of the film are measured and analyzed by ellipsometry. It is found that the refractive index n and extinction coefficient k of KTN thin films decrease with the increase of wavelength in both visible and near infrared wavelengths, which are consistent with the normal dispersion Cauchy model.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O484

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