Wang Zujian, He Jiangang, Hu Bing, Shan Pai, Xiong Zheyao, Su Rongbing, He Chao, Yang Xiaoming, Long Xifa
Key Laboratory of Optoelectronic Materials Chemistry and Physics, State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter , Chinese Academy of Sciences , Fuzhou , Fujian 350002 , China.
Department of Materials Science and Engineering , Northwestern University , Evanston , Illinois 60208 , United States.
ACS Appl Mater Interfaces. 2020 Jan 29;12(4):4632-4637. doi: 10.1021/acsami.9b21072. Epub 2020 Jan 16.
MBOX is a prominent family with excellent nonlinear optical (NLO) responses, just as the PbBOI crystal with a large second harmonic generation (SHG) of 13.5 times that of KHPO. However, most of these compounds are limited to ultraviolet and visible regions because of their long absorption edge (small band gap). Here, we report two members of this family, which change the situation. Using a high-temperature solution method, we obtain CaBOCl and SrBOCl crystals, which exhibit a deep-ultraviolet (DUV) absorption edge of 170 nm (band gap ≈ 7.29 eV). It is an important breakthrough in the DUV transparency of the MBOX family. Furthermore, CaBOCl crystals display a phase-matching SHG response under a 1064 nm laser, which is further confirmed by the balance between the suitable birefringence and the small dispersion of refractive indexes in the wavelength range of 1064-532 nm. Therefore, they are promising DUV transparency windows and NLO candidates.
MBOX是一个具有出色非线性光学（NLO）响应的重要家族，就像PbBOI晶体一样，其二次谐波产生（SHG）大，是KHPO的13.5倍。然而，由于这些化合物的吸收边较长（带隙小），它们大多局限于紫外和可见光区域。在此，我们报道了该家族的两个成员，它们改变了这种情况。采用高温溶液法，我们获得了CaBOCl和SrBOCl晶体，它们表现出170 nm的深紫外（DUV）吸收边（带隙≈7.29 eV）。这是MBOX家族在深紫外透明度方面的一个重要突破。此外，CaBOCl晶体在1064 nm激光下表现出相位匹配的SHG响应，这在1064 - 532 nm波长范围内合适的双折射与小的折射率色散之间的平衡中得到了进一步证实。因此，它们是很有前景的深紫外透明窗口和NLO候选材料。
