Hierarchized bandgap and enhanced optical responses from(d-p)π conjugated interaction in trivalent rare-earth metal nitrates
Introducing NO3 groups or some rare-earth metals is one strategy to obtain potential optical functional materials without influencing the transmittance in ultraviolet(UV)/deep-UV region.In this work,a new crystal,Na4La2(NO3)10·2H2O(NLN)containing these two units was obtained for the first time by slow evaporation method at room temperature with dimensions of 3 × 2 × 0.75 mm3.It processes an anomalous high UV cutoff edge totally different to alkali/alkaline-earth metals nitrates and rare-earth metal borates.Meanwhile,K2La(NO3)5·2H2O(KLN)whose structure similar to NL·N have a noticable improvement in linear optical property compared NLN and a large second harmonic generation effect.To clarify the inner mechanism or synergy of NO3 and rare-earth metals on influencing electronic structure and optical properties,the trivalent rare-earth metal nitrates such as Na4La2(NO3)10·2H2O and K2La(NO3)5·2H2O have been studied systematically by the first-principles in comparison with related borates.It reveals that the unique(d-p)π interaction generating from trivalent rare-earth metal and oxygen of NO3 hinders the large band gap,enhances the second harmonic generation(SHG)effect and strengthens optical anisotropy when the coordination environment is non-uniform in electronegativity.In particular,the hierarchical band gap is related to the degree of interaction that depends on the delocalization of O-2p orbitals in the groups,which offers a way to design new functional materials with special characters by controlling cations or anionic groups.
Bing-Hua Lei Qingrong Kong Zhihua Yang Yun Yang Ying Wang Shilie Pan
Key Laboratory of Functional Materials and Devices for Special Environments,Xinjiang Technical Insti Key Laboratory of Functional Materials and Devices for Special Environments,Xinjiang Technical Insti Key Laboratory of Functional Materials and Devices for Special Environments,Xinjiang Technical Insti
国内会议
大连
英文
813-822
2016-09-24（万方平台首次上网日期，不代表论文的发表时间）