俄罗斯Skoltech大学Artem R. Oganov对具有优良深紫外非线性光学性能的新型范德华硼氧化物进行了预测。 相关研究成果于2021年2月25日发表在《德国应用化学》。

深紫外非线性光学（DUV-NLO）材料因其结构的多样性和复杂性而越来越受到人们的关注。

利用二维（2D）晶体结构预测方法结合第一性原理计算，研究人员发现了新的范德华（VDW）层状18元环（18MR）氧化硼B₂O₃多晶型高性能非线性光学材料。具有AA和AB堆垛结构的118MRB₂O₃是潜在的DUV  NLO材料。优越性能的AB堆垛使二次谐波产生系数达到了前所未有的1.63pm/V，是具有DUV吸收边的NLO材料中最大的，是先进的DUV NLO材料KBe2BO3F2的三倍，与βBaB2O4相当。

AB堆垛在400 nm处的0.196的异常大的双折射保证了相位匹配波长λ PM达到该材料~154 nm的极端吸收边缘。通过改变18MRB2O3中的堆垛层数可以调节性能，这为进一步增强提供了一种有效的方法。

研究人员预测VDW晶体优异的非线性光学特性可以在2D和3D两个方面进行探索。

附：英文原文

Title: Prediction of Novel van der Waals Boron Oxides with Superior Deep‐Ultraviolet Nonlinear Optical Performance

Author: Hao Li, Jingmei Min, Zhihua Yang, Zhenhai Wang, Shilie Pan, Artem R. Oganov

Issue&Volume: 2021-02-25

Abstract: Deep‐ultraviolet nonlinear optical (DUV NLO) materials and their predictions are attracting increasing attention because of their structural diversity and complexity. Using the two‐dimensional (2D) crystal structure prediction method combined with the first‐principles calculations, here we discovered new van der Waals (VDW) layered 18‐membered‐ring (18MR) boron oxide B  2  O  3  polymorphs as high‐performance NLO materials. 18MRB  2  O  3  with the  AA  and  AB  stackings are potential DUV NLO materials. The superior performing  AB  stacking results in an unprecedentedly high second harmonic generation coefficient of 1.63 pm/V, the largest among the NLO materials with a DUV absorption edge and being three times larger than that of the advanced DUV NLO material KBe  2  BO  3  F  2  and comparable to that of βBaB  2  O  4  . The  AB  stacking’s unusually large birefringence of 0.196 at 400 nm guarantees the phase‐matching wavelength λ  PM  to reach this material’s extreme absorption edge of ~154 nm. The performance can be tuned by varying the layer stackings in 18MRB  2  O  3  , which provides an efficient approach for further enhancement. We predict that excellent NLO properties of VDW crystals can be explored in 2D and 3D with promising possibilities.

DOI: 10.1002/anie.202015622

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202015622