Ag4Hg(SeO3)2(SeO4): a novel SHG material created in mixed valent selenium oxides by in situ synthesis

Abstract

Explorations of new second harmonic generation materials in Ag + -Hg 2+ /Bi 3+ -selenites systems afforded three new silver selenium oxides, namely, Ag 4 Hg(SeO 3 ) 2 (SeO 4 ) (1), Ag 2 Bi 2 (SeO 3 ) 3 (SeO 4 ) (2) and Ag 5 Bi(SeO 3 ) 4 (3). They exhibit flexible crystal chemistry. Compounds 1 and 2 are mixed valence selenium oxides containing Se(IV) and Se(VI) cations simultaneously. Compounds 1 and 3 exhibit a 3D open framework with 4-, 6-and 8-member polyhedral ring tunnels along a, b and c axes. Compound 1 crystallized in a polar space group and could display a subtle frequency doubling efficiency about 35% of the commercial KH 2 PO 4 (KDP). UV-vis-NIR spectra reveal that compounds 1-3 are wide-band semiconductors with the optical bandgaps of 3.11, 3.65, 3.58 eV respectively. Theoretical calculations disclose that compounds 2 and 3 are indirect band gap structures and their bandgaps are determined by Ag, Bi, Se and O atoms together.

Linear and Nonlinear Optical Properties of Centrosymmetric Sb4O5SO4 and Noncentrosymmetric Sb4O4(SO4)(OH)2 Induced by Lone Pair Stereoactivity

“…Lasers with different wavelengths are widely applied in both civil and military fields, such as precision manufacturing, laser medicine, remote communication, optoelectronic devices, and so forth. − Nonlinear optical (NLO) materials can achieve the tunable laser output by frequency conversion and are of great interest for scientists. − Over the past few decades, some commercial NLO crystals, such as AgGaX 2 (X = S, Se), , ZnGeP 2 , KTiOPO 4 , KH 2 PO 4 , β-BaB 2 O 4 , LiB 3 O 5 , have been developed. However, with the development of technologies, these crystals cannot satisfy the increasing requirements of frequency conversations in the whole wavelength region.…”

“…), is an effective way to achieve noncentrosymmetric (NCS) structures and further strengthen the SHG effect. For example, a series of NLO materials containing SCALP cations of Te 4+ , Se 4+ , Bi 3+ , and Pb 2+ were developed, such as Bi 3 TeO 6 OH­(NO 3 ) 2 , Ag 4 Hg­(SeO 3 ) 2 (SeO 4 ), Bi 3 (TeO 6 )­(BO 3 ), Bi­(IO 3 )­F 2 , Pb 2 BO 3 I, and Pb 2 B 5 O 9 I . However, in comparison, Sb­(III)-based ultraviolet (UV) NLO materials are limited until now.…”

Structure, Photoluminescence Emissions, and Photocatalytic Activity of Ag2SeO3: A Joint Experimental and Theoretical Investigation

“…In recent decades, metallic selenites have attracted great attention because of their different chemical structures and advanced physical properties such as pyroelectricity, ferroelectricity, and piezoelectricity, and their important role in human health, especially because selenium is an elemental component of several selenoproteins . Selenites can be considered as important lone-pair oxyanions, in which stereoactive nonbonded electron pairs are present and active free electron pair of the Se 4+ cations can induce second-order Jahn–Teller distortions and the formation of noncentrosymmetric or polar structures. − …”

Syntheses, characterization, and theoretical calculation of Rb2Mg3(P2O7)2 polymorphs with deep-ultraviolet cutoff edges

“…Nonlinear optical (NLO) materials particularly for ultraviolet (UV) or deep-UV have attracted great concern owing to the ability of expanding the limited laser wavelengths to much wider spectral regions by different frequency conversion. They have been widely used in laser science, photolithography and advanced instrument process [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Borates possess an absolute advantage for developing UV or deep-UV NLO materials because they have wide optical transparency windows, relatively large second-harmonic generation (SHG) responses and abundant acentric structure units.…”