锂化硼氮纳米管的二阶非线性光学理论研究  

Theoretical Study on Second-order Nonlinear Optical Response of Lithiation Boron Nitride Nanotube

作　　者：周中军[1,2] 李晓平[3] 黄旭日[1] 武志坚 李志儒[1] 

机构地区：[1]吉林大学理论化学研究所,理论化学计算国家重点实验室,长春130021 [2]长春应用化学研究所,稀土资源利用国家重点实验室,长春130022 [3]曲阜师范大学化学与化工学院,曲阜273165

出　　处：《高等学校化学学报》2013年第9期2152-2157,共6页Chemical Journal of Chinese Universities

基　　金：国家'九七三'计划项目(批准号:2012CB932800);国家自然科学基金(批准号:21173097;21173098;21073075和20100061110046);中国博士后基金(批准号:2012M510896)资助

摘　　要：基于硼氮纳米管（BNNTs），研究了多重锂化硼氮纳米管Lin-（n，O，l）BNNTs（n=6和8，l=2～4）的结构与非线性光学性质．研究表明，在Lin-（n，0，l）BNNTs中，Li原子上的自然键轨道电荷接近＋1（0．769～0．827e），表明“原子上的电子转移到了硼氮纳米管上，从而形成了多重锂盐．同时发现，增加管长和拓宽管径都可有效地增加体系的一阶超极化率．更重要的是，Lin-（n，0，l）BNNTs的紫外-可见吸收主要发生在270—290nm附近，且当管长增加时，Lia^-（n，0，l）BNNT的紫外一可见吸收光谱发生了蓝移，改善了非线性与透光性之间的关系．此外，Lin-（n，0，l）BNNTs还具有良好的稳定性[垂直电离势（VIP）=5．85～6．0eV]．The development and application of second-order nonlinear optics （NLO） materials are always blocked by the nonlinearity-transparency trade-off. Improving this problem has become one of the most important researches in this field. In this paper, based on boron nitrogen nanotubes （ BNNTs）, the structures and nonlinear optical properties of lithiation boron nitrogen nanotubes Lin-（ n, 0,1）BNNTs （n = 6 and 8, l = 2---4 ） were studied in theory. The results show that there are strong charge transfers occurring from Li atoms to boron nitrogen nanotubes, and the natural bond orbital（NBO） charges of Li atoms in Lin-（n,0, l）BNNTs are 0. 769-0. 827 e, which is very close to ＋1, indicating that the multilithium salts of Lin-（n,0,1） BNNTs are formed. And we found that with the increasing of the length and the width of tubes, first hyperpolarizabilities regularly increase. What is more important is that the UV-Vis adsorptions for Lin-（ n,0 ,1）BNNTs are mainly near 270--290 nm. When increasing the length of tubes, Lin-（n,0,1）BNNTs have a small blue-shift, improving the nonlinearity-transparency trade-off. Besides, Lin-（ n,0, 1）BNNTs also have large vertical ionization potentials （ VIPs = 5.85-6. 00 eV）, exhibiting higher stabilities. And thus Lin- （ n, 0, 1） BNNTs may be pro- mising candidate for high-performance nonlinear optical materials.

关 键 词：硼氮纳米管 非线性光学 锂化 透光性 

分 类 号：O641[理学—物理化学]