基于离子替代的(碱土,铅)硼酸盐系列倍频晶体制备及结构-效应-带隙的关系规律研究

项目名称： 基于离子替代的(碱土,铅)硼酸盐系列倍频晶体制备及结构-效应-带隙的关系规律研究

项目编号： No.U1503193

项目类型： 联合基金项目

立项/批准年度： 2016

项目学科： 管理科学

项目作者： 张方方

作者单位： 中国科学院新疆理化技术研究所

项目金额： 50万元

中文摘要： 短波长倍频晶体是固体激光器输出紫外、深紫外激光的关键材料。晶体的倍频效应和带隙是其重要性能指标，两者相互影响、制约，使设计合成具有较大倍频效应和短紫外截止边的晶体成为难点，探明晶体结构与上述两种光学性质的关系对材料设计具有重要指导意义。已有的倍频晶体由于体系各不相同，元素种类、组成、结构差异较大，难以系统研究结构-性质的关系规律。申请人前期成功制备了两个简单二元铅硼酸盐化合物Pb4B2O7和Pb6B6O15，粉末倍频效应是KDP的3~3.5倍，能实现1064nm基频波相位匹配，不潮解，无层状生长习性，结构中铅离子的存在导致吸收边红移。本项目以此为结构基础，将铅离子替代为在紫外区无吸收的碱土金属离子，制备系列(碱土,铅)硼酸盐晶体，研究由此引起的晶体结构/电子结构递变规律及其对倍频效应、带隙产生的影响，构建该体系晶体组成、结构与这两种光学性质的关系，探索具有较大倍频效应和短紫外截止边的材料。

中文关键词： 短波长倍频晶体；制备；结构-性能关系；离子替代；电子结构

英文摘要： Short-wavelength frequency-doubling crystal is the key material of the solid state laser for producing ultraviolet or deep ultraviolet light. The frequency-doubling efficiency and optical band gap of the materials are the most important properties for short-wavelength frequency-doubling crystals. Both properties affect and constrain each other, which make it difficult to design and synthesize materials with low cut-off edge and appropriate frequency-doubling efficiency. Therefore, exploring the relationship between crystal structure (or electronic structure) and these two optical properties is very important for materials design. Recently, several frequency-doubling crystals were discovered, however, which are quite different in their compositions and structures, making it difficult to investigate the structure-properties systematically. In the previous work, we successfully synthesized two simple binary lead borates, Pb4B2O7and Pb6B6O15. Both crystals are phase matchable at the fundamental wavelength of 1064 nm, and the powder frequency doubling efficiencies are approximately 3 to 3.5 times that of KDP. They are not hygroscopic or having layer growth habit. The presences of lead cations in both structures lead to a red shift of the absorption edges and the band gaps of both crystals are approximately 3.5 eV. Based on the structural foundations of Pb4B2O7and Pb6B6O15, this project tries to substitute the lead cations for alkaline-earth metal cations which would not absorb light in the ultraviolet range. We will synthesize a series of (alkaline-earth, lead)borates and systematically study the changes of crystal structures and electronic structures, as well as their effects on their optical properties, i.e., frequency-doubling efficiency and band gap. We try to construct a relationship between the composition/structure and the optical properties, and search for good frequency-doubling crystals with short cut-off edge and appropriate frequency-doubling efficiency.

英文关键词： short-wavelength frequency-doubling crystal ; synthesis ;structure-properties relationship;ion substitution ;electronic structure