2D van der Waals Layered [C(NH2)3]2SO3S Exhibits Desirable UV Nonlinear-Optical Trade-Off

Youchao Liu; Xiaomeng Liu; Zheyao Xiong; Binwen Liu; Jinlong Xu; Lina Li; Sangen Zhao; Zheshuai Lin; Maochun Hong; Junhua Luo

doi:10.1021/acs.inorgchem.1c02555

2D van der Waals Layered [C(NH₂)₃]₂SO₃S Exhibits Desirable UV Nonlinear-Optical Trade-Off

Inorg Chem. 2021 Oct 4;60(19):14544-14549. doi: 10.1021/acs.inorgchem.1c02555. Epub 2021 Sep 22.

Authors

Youchao Liu¹, Xiaomeng Liu², Zheyao Xiong^{1

3}, Binwen Liu¹, Jinlong Xu⁴, Lina Li^{1

5}, Sangen Zhao^{1

3

5}, Zheshuai Lin^{2

3}, Maochun Hong^{1

5}, Junhua Luo^{1

3

5}

Affiliations

¹ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
² Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
³ University of the Chinese Academy of Sciences, Beijing 100049, China.
⁴ National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210093, P. R. China.
⁵ Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, Fujian 350108, P. R. China.

PMID: 34549955
DOI: 10.1021/acs.inorgchem.1c02555

Abstract

It remains a challenge to develop UV nonlinear optical (NLO) crystals that can achieve a desirable trade-off on UV absorption edge, second harmonic generation (SHG), and birefringence. Here we report a thiosulfate UV NLO crystal of a 2D van der Waals layered structure, [C(NH₂)₃]₂SO₃S. Remarkably, this thiosulfate realizes the desired trade-off, with a short absorption edge of 254 nm, a strong SHG response of approximately 2.8 times that of the benchmark KH₂PO₄, and a sufficient birefringence of 0.073 at the wavelength of 546 nm. In addition, it exhibits strong in-plane anisotropy of the SHG intensity. According to the first-principles calculations, the non-π-conjugated [SO₃S]^2- anion is the dominant SHG functional gene, while the π-conjugated [C(NH₂)₃]⁺ cation serves as the functional gene of birefringence. This is different from common UV NLO materials whose functionals of SHG and birefringence are the same. These findings indicate that combining different function genes may be an effective strategy to develop outstanding NLO materials with the desirable property trade-off.