【作者】 孙彧；

【导师】 姜兆华； 杨春晖；

【作者基本信息】 哈尔滨工业大学 ， 化学工程与技术， 2012， 博士

【摘要】 ⅤA族和ⅤB族元素含氧酸盐是两类重要的非线性光学晶体，KDP和ADP、LiNbO₃和LiTaO₃分别为这两类晶体的典型代表。它们的体材料具有优良的光学及光谱特性，其外延材料及掺杂外延材料由于具有微-纳尺度结构而呈现更丰富的光谱特性。因此，本文依据这四种晶体适合进行水相外延的结晶学特性，进行了过饱和溶液结晶法生长KDP/ADP晶体异质外延层及二甲酚橙掺杂研究和水热法生长稀土Er³⁺/Yb³⁺掺杂LiNbO₃和LiTaO₃晶体同质掺杂外延层研究，并重点讨论了材料的光谱特性。根据溶度积原理，对KDP/ADP体系晶体（KDP和ADP的混合晶体记做KADP）生长过程及规律进行了较系统的分析。以光学显微镜分析了晶体界面形貌，结果表明，晶体表面的微观生长纹理与相应晶面所体现的宏观几何形状呈现自相似特征；以X-射线衍射谱分析了样品的物相，以热分解方法分析了样品的化学组成，结果表明，KDP/ADP混合体系的结晶产物为四方相，组分随结晶过程变化；以空间群分析结果为基础，获得了KDP/ADP晶体体系红外吸收峰和拉曼频移峰的光谱归属。以上结果将作为过饱和溶液结晶法异质外延生长KDP/ADP晶体及其光谱特性研究的基础。分别以KDP和ADP晶体为衬底，在ADP和KDP饱和溶液中进行了异质外延层生长。其显微形貌表明：（1）在不同的晶面上，微小的生长点与该晶面的宏观几何形状自相似；（2）通常认为外延过程依赖于晶格匹配，但在本实验体系中，主要的影响因素是界面微观几何形貌；（3）外延界面的生长点在微观形貌方面体现了KDP/ADP混合晶体的结晶学特征。KDP/ADP外延层的普通拉曼光谱和微拉曼光谱呈现了不同的Raman峰，前者与以往的文献可形成对照，而后者与以往的文献差异较大。分析结果表明，其原因可能来自于两方面：（1）由于样品是非线性光学材料，在高能高功率密度情况下，样品的极化效应明显；（2）样品界面形成的微-纳米尺度结构引起了非线性光学效应。进行了二甲酚橙（XO）染料掺杂KDP和ADP晶体及异质外延生长实验，分析了XO在KDP和ADP晶体及异质外延过程中的着色规律。依据XO在KDP和ADP晶体中着色各向异性的现象,讨论了不同晶面的相对生长速率。测试并分析了XO-KDP和XO-ADP的吸收光谱，结果表明，两者呈现颜色不同的原因在于，NH4+与XO阴离子的作用使XO-ADP在红光波段的吸收远大于XO-KDP。X-射线衍射物相分析结果表明，由于晶格匹配因素影响，XO掺杂有利于ADP/XO-KDP生长，但不利于KDP/XO-ADP外延生长。ADP/XO-KDP和KDP/XO-ADP外延生长界面的微拉曼光谱测试及分析结果表明：（1）XO荧光可抬高样品的声子响应背底；（2）XO对晶格常数匹配度的改变将影响声子宽谱拉曼频移，匹配度提高，声子宽谱拉曼频移越弱；（3）XO阴离子与NH4+离子存在强的相互作用，使[NH4]基团在高功率下，结构更稳定。分析了水热法同质外延离子源母液的性质及水热法外延反应过程，并在此基础上，实现了在LiNbO₃和LiTaO₃晶体衬底上生长稀土Er³⁺/Yb³⁺掺杂外延层。形貌及元素分析表明，母液中各种金属离子和F-离子浓度不宜过高，pH值应为3⁴。改进了稀土离子J-O理论计算过程，引入与浓度和厚度有关的kNL待定参数，使J-O理论拟合计算适用于任何未知浓度和厚度的+3价稀土离子掺杂体系。对Er³⁺/Yb³⁺掺杂LiNbO₃和LiTaO₃外延层进行了基于吸收光谱的拟合计算，结果呈现出Er³⁺/Yb³⁺掺杂LiNbO₃和LiTaO₃单晶的光谱参数特征。上转换发光测试及光谱参数计算分析结果表明：在Er³⁺/Yb³⁺离子的掺杂浓度比为1:1的情况下，样品呈现绿色上转换发光光谱；以降低基质声子能量的方法提高⁴I_13/2能级对²H_11/2和⁴S_3/2能级的量子剪裁效率。更多还原

【Abstract】 The oxysalts of V A and V B group elements are two important types ofnonlinear optical crystals, in which KDP and ADP, LiNbO₃and LiNbO₃aretypical representatives of these two types of crystals. Respectively, the bulkmaterials posses excellent optical and spectral characteristics, and more spectralproperties of epitaxial materials and their doped materials may be obtained dueto the special micro-and nano-structures. As these four crystals are suitable forthe crystallization characteristics of the water phase epitaxy growth, we carriedout the theoretical and technological research on the supersaturated solutiongrowth of KDP/ADP crystal hetero-structure and its epitaxial layer with xylenolorange doping, as well as the hydrothermal growth of rare earth ions Er³⁺/Yb³⁺-doped LiNbO₃and LiTaO₃crystals with homogeneity doped epitaxial layers. Inaddition, the spectral properties of these materials were discussed intensively.The crystal growth rules of mixture crystals KADP （potassium dihydrogenphosphate （KDP） and ammonium dihydrogen phosphate （ADP）） have beenanalyzed based on the solubility product principle. The morphology of crystalinterface is analyzed by means of optical microscopes. The results reveal that themicro-growth texture on the crystal surface shows self-similar behavior with itsmacro-geometry on the corresponding crystal planes. The crystallization phaseand chemical composition of the samples are analyzed by X-ray diffraction andthermo-gravimetric. It is shown that self-similar with the micro-growth textureof the crystal surface and the corresponding crystal face reflected in macro-geometry; sample phase analysis by X-ray diffraction pattern, and the chemicalcomposition analysis by thermo-gravimetric, The results showed that productphase of KDP/ADP mixture system crystallization is tetragonal phase, and thecomposition changes with the crystallization process; Spectra attribution forpeaks of infrared absorption and Raman frequency shift on the KDP/ADPcrystal systems, is obtained based space group theory. These results will serve asthe basis of hetero-epitaxial growth in KDP/ADP crystal system by saturatedsolution crystallization method and its spectral characteristics.The heteroepitaxial layers have been obtained by immersing KDP （ADP）substrate into the ADP （KDP） saturated solut. The micromorphology indicates that small growing points on different planes show the self-similar propertycompared to the morphology of bulk crystal. The process of epitaxial growthdepends on not the lattice match but the crystallizing kinetics, which is the maininfluencing factor. Moreover, it can be inferred from the micromorphology onthe surface of the mixed crystal that the dissolving of substrates will form mixedsolution on the epitaxial surface. What’s more, corrosion phenomenon becomesmore and more evident with increasing time of epitaxial growth and it will behard to form transparent epitaxial layers due to increasing tension of epitaxiallayers.It is interesting that during the process of testing, different Raman peakscould be observed via different apparatuses. Raman peaks through LabRAMHR800are consistent with the previous references. However, the resultsobtained with Renishaw2000micro-Raman spectroscopy show large deviationswith the previous references. One reason for this difference is the evidentpolarization effect under high energy and power density. Another probablereason is the special microstructures which formed during the growth would leadto special micro-nano optical effects.The phenomenon of dye coloring anisotropy has been discovered in crystalgrowth process of potassium dihydrogen phosphate （KDP） and potassiumdihydrogen phosphate （ADP） doped with xylenol orange dye, and the obviousboundary could be seen in colored region. The absorption spectra of the XO-KDP and XO-ADP are measured and analyzed. The results show that theabsorption of the XO-ADP in the red band is much larger than that of the XO-KDP which is due to the role of NH4+and XO anions. X-ray diffraction analysisresults show that XO doping is beneficial to the ADP/XO KDP growth becauseof the lattice match, but not to KDP/XO-ADP epitaxial growth. The micro-Raman spectroscopy analysis of interface of ADP/XO-KDP and KDP/XO-ADPepitaxial growth results showed that:（1） The XO fluorescence can raise thebackground of samples phonon response;（2） XO will affect the phonon widespectra of Raman frequency shift, because of the change of the lattice constantmatching. The higher the lattice constant matching is, the weaker of phononspectrum of the Raman frequency shift is.（3） In particular, in terms of KDP/XO-ADP, the strong interaction between the XO anions and NH4+ions makes thestructure of [NH4] groups more stable in the intensity power. The properties of hydrothermal method homo-epitaxial ion source motherliquor and the extension reaction process of the hydrothermal method wereanalyzed. On this basis, the growth of rare earth Er³⁺/Yb³⁺-doped epitaxial layeron the LiNbO₃and LiTaO₃crystalline substrates was achieved. The morphologyand elemental analysis showed that concentration of metal ions and F-ion in themother liquor should not be too high, and the pH value should be controlledbetween3⁴. The absorption spectra of the samples were measured, and theundetermined parameter kNLwhich is related to the concentration and thicknessis intruced the research of fitting calculation is conducted on the bases ofabsorption spectrum about the hydrothermal epitaxial polycrystalline sample onthe surface of LiNbO₃and LiTaO₃doped with Er³⁺/Yb³⁺single crystallinesubstrate according to J-O theory at the room temperature. This method can beextended to the system without direct access to the data of concentration andthickness such as powder or colloid. According to the rate equation and theconsequence calculated via spectrum parameters, this paper confirms that boththe Er³⁺/Yb³⁺doping ratio and excitation light power are able to influence thered-green up-conversion luminescence spectrum; the method of reducing theenergy of matrix phonon shall be tried to improve the quantum cutting yield of⁴I_13/2to²H_11/2and⁴S_3/2.更多还原