Rational Crystal Structure Design and Nonlinear-Optical Properties of Noncentrosymmetric RbCu2NbS4

• Published in: Inorganic chemistry Vol. 61; no. 1; pp. 657 - 663
• Main Authors: Luo, Mengjia, Huang, Chong, Lin, Feng, Che, Xiangli, Zhang, Xian, Huang, Fuqiang
• Format: Journal Article
• Language: English
• Published: American Chemical Society 10.01.2022
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.1c03215

Crystal structure design based on known materials is an efficient strategy for exploring new compounds with evident second-harmonic-generation (SHG) effects. By the introduction of Rb+ ions into the 3D framework of Cu3NbS4, the new compound RbCu2NbS4 (space group Ama2) composed of [ Cu 2 2 ∞ Nb S 4 ] − layers is obtained. The band gap of RbCu2NbS4 is 2.1 eV, indicating that this compound is a semiconductor. Band-structure calculations indicate that the electronic transition mainly occurs from the S 3p/Cu 3d to Nb 4d states. The intercalation of Rb+ ions induces a high degree of local distortion and symmetry reduction, which results in a dipole moment of 11.7 Debye for RbCu2NbS4. RbCu2NbS4 shows a moderate SHG response of 0.33 × AgGaS2 (particle size of 20–41 μm).