Key Factors Controlling the Large Second Harmonic Generation in Nonlinear Optical Materials
Key Factors Controlling the Large Second Harmonic Generation in Nonlinear Optical Materials
复制标题
控制非线性光学材料中产生大量二次谐波的关键因素
DOI：
10.1021/acsami.9b20023
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发表时间：
2020-02-26
影响因子：
9.5
通讯作者：
Deng, Shuiquan
中科院分区：
文献类型：
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作者：
Cheng, Xiyue;Li, ZhenHua;Deng, Shuiquan
用密度泛函理论（DFT）计算了非同构非线性光学（NLO）化合物β-BaB_2O_4、LiB_3O_5、CsB_3O_5、CsLiB_6O_（10）、KBe_2BO_3F_2和LiCs_2PO_4的二次谐波（SHG）响应，并通过原子响应理论分析确定了它们的阳离子和阴离子对SHG响应的贡献.在所有这些化合物中，所有金属阳离子的贡献位于总SHG响应的近似9.3%至近似29.7%的范围内，并且所有阴离子的贡献位于近似57.4%至近似72.3%的范围内。然而，就单个原子的贡献而言，大的金属阳离子可以比阴离子对总的SHG响应贡献更多。我们的工作表明，单个阴离子（例如，O2-）在与其周围的阳离子（例如，O-B）。单个阳离子的贡献进一步受到其周围阴离子分布的均匀性的影响，并且还受到其周围阴离子的极化率通过与其他阳离子的共价键合而减弱的程度的影响。SHG响应随着α（sum）/（NEg）而增加，α（sum）/（NEg）是在寻找新的NLO材料中有用的重要参数，其中α（sum）是原始晶胞中所有离子的极化率之和，N是每个原始晶胞的原子总数，并且E-g是带隙。
The second harmonic generation (SHG) responses of nonisostructural nonlinear optical (NLO) compounds, beta-BaB2O4, LiB3O5, CsB3O5, CsLiB6O10, KBe2BO3F2, and LiCs2PO4, were examined by density functional theory (DFT) calculations, and the contributions of their individual cations and anions were determined by performing atomic response theory analyses. In all of these compounds, the contribution of all metal cations lies in the range of similar to 9.3 to similar to 29.7% of the total SHG responses, and that of all anions lies between similar to 57.4 and similar to 72.3%. However, in terms of individual atom contribution, a large metal cation can contribute more than does an anion to the total SHG response. Our work shows that the SHG contribution of an individual anion (e.g., O2-) is weakened when it forms covalent bonds with its surrounding cations (e.g., O-B). The contribution of an individual cation is further affected by the homogeneity of its surrounding anion distribution and also by how strongly the polarizabilities of its surrounding anions are weakened by covalent bonding with other cations. The SHG response increases with alpha(sum)/(NEg), an important parameter useful in searching for new NLO materials, where alpha(sum) is the sum of the polarizabilities of all of the ions in the primitive unit cell, N is the total number of atoms per primitive cell, and E-g is the band gap.