Four UV Transparent Linear and Nonlinear Optical Materials Explored from Pure Selenite Compounds

Abstract

UV nonlinear optical materials require the simultaneous achievement of a large second harmonic generation (SHG) coefficient (≥1 × KH2PO4 (KDP), dij > 0.39 pmV−1), wide bandgap (λ < 300 nm, Eg > 4.2 eV), and moderate birefringence (0.05‐0.10@1064 nm) in a single structure. Therefore, designing UV nonlinear optical materials with excellent comprehensive performance is a challenging task. Herein, four UV transparent selenite materials are successfully obtained, namely, Al2(SeO3)3(H2O)3 (1), Ga2(SeO3)3(H2O)3 (2), NaGa3(HSeO3)6(SeO3)2 (3), and Cd5Ga4(HSeO3)2(SeO3)10 (4), through rational design and screening in the pure selenite system. Al2(SeO3)3(H2O)3 (1) and Ga2(SeO3)3(H2O)3 (2) are UV nonlinear optical materials with balanced properties, exhibiting moderate SHG responses (1.2 and 1.1 × KDP), appropriate birefringence (0.084 and 0.076@1064 nm), and wide bandgaps (5.5 and 5.3 eV). Such bandgaps are the largest in the reported pure selenite nonlinear optical (NLO) materials. This work further demonstrates that pure selenite is a good candidate for UV NLO materials.

Hg3Se(SeO3)(SO4): A Mixed-Valent Selenium Compound with Mid-Infrared Transmittance Obtained by In Situ Reaction

“…The theoretical calculation of the birefringence (Δn) is 0.064@546 and 0.058@1064 nm (Figure 4b), which are close to the experimental values. It is comparable to the values of compounds Ga 2 (SeO 3 ) 3 (H 2 O) 3 (0.076@1064 nm) 18 and Lu(SeO 3 )(HSeO 3 )(H 2 O)•(H 2 O) (0.065@1064 nm). 25 Considering its wide transmission range and high LIDT, it shows that Hg 3 Se(SeO 3 )(SO 4 ) can be a potential MIR birefringent material.…”

“…These compounds can be synthesized easily due to the absence of competition from other anionic groups. Among them, NaLu­(SeO 3 ) 2 , Sc­(HSeO 3 ) 3 , and Ga 2 (SeO 3 ) 3 (H 2 O) 3 have potential applications in the ultraviolet (UV) region. The mixed-anion selenite system refers to compounds that contain two or more different anionic groups. , These compounds can combine the advantages of various anionic groups to obtain materials with an excellent overall performance.…”

UV-Transparent SHG Material Explored in an Alkali Metal Sulfate Selenite System

“…We can see that selenites with a band gap higher than 5.5 eV are still very rare. Only four compounds, namely, Y(HSeO 3 )(SeO 3 )(H 2 O)• (H 2 O) (5.5 eV), 44 Al 2 (SeO 3 ) 3 (H 2 O) 3 (5.5 eV), 45 Gd(NO 3 )-(Se 2 O 5 )•3H 2 O (5.53 eV), 46 and NH 4 (GaF 2 ) 3 (SeO 3 ) 2 (5.77 eV), 47 were reported before our work. From Table S6, we can see that Na 8 (SeO 3 )(SO 4 ) 3 (1) is the only selenite sulfate with a band gap higher than 5.0 eV.…”

A UV non-hydrogen pure selenite nonlinear optical material for achieving balanced properties through framework-optimized structural transformation

“…Furthermore, Ga 3+ tends to exhibit a six-coordinated environment, and the GaO 6 octahedra are isolated in NaGa(SeO 3 ) 2 , requiring bridging SeO 3 groups to construct the framework. 34,45,46 While Lu 3+ typically adopts a higher coordination number, 47 the Lu polyhedra readily undergo polymerization. The substitution of Ga 3+ with Lu 3+ is expected to optimize the framework of NaGa(SeO 3 ) 2 and achieve a structural transformation from CS to NCS space group.…”