From Cs8Sb4Nb5O5F35 to Cs6Sb4Mo3O5F26: The first noncentrosymmetric fluoroantimonite with d0 transition metal

From H12C4N2CdI4 to H11C4N2CdI3: a highly polarizable CdNI3 tetrahedron induced a sharp enhancement of second harmonic generation response and birefringence

“…[28][29][30][31][32][33][34] However, on the one hand, the use of SCLAP cations is known to cause red shis in absorption edges and reduce bandgaps of the resulting crystals, limiting their potential applications in the ultraviolet (UV) and deep-UV regions. [35][36][37][38][39][40] For instance, Mao's group recently reported a series of Ge 2+ -containing OIMHs, in which (CH 3 NH 3 )GeBr 3 shows a large SHG response (5. 44 and ((CH 3 ) 3 NCH 2 Cl)CdCl 3 , 46 usually possess wide bandgaps (>5.0 eV) but relatively weak SHG effects (<1.0 × KDP).…”

From CdPb8(SeO3)4Br10 to Pb3(TeO3)Br4: the first tellurite bromide exhibiting an SHG response and mid-IR transparency

“…[7][8][9][10] According to the ICSD database, the probability of obtaining a non-centrosymmetric structure is less than 20%. [11][12][13] So, the rational design of inorganic compounds with non-centrosymmetric symmetry remains a challenging but beneficial task for researchers in chemical and materials science.…”

“…17 Known nonlinear active units include, but are not limited to, d 0 transition metal octahedra (TiO 6 , MoO 6 , WO 6 , VO 6 , NbO 6 , etc.) 11,18 and their derivatives (GaO 6 , GaO 3 F 3 , etc. ), [19][20][21] d 10 transition metals with large polar displacement (Zn 2+ , Cd 2+ , Hg 2+ ), 22,23 and SALP cations (Pb 2+ , Bi 3+ , Sn 2+ , Sb 3+ , etc.).…”

AAl(Te4O10) (A = Na, Ag) and K2Ga2(HTe6O16)(HTeO3): Three Aluminum/Gallium Tellurites with Large Birefringence and Wide Band Gap

“…Some recent literature studies have proven this, such as PbVTeO 5 F (0.142 at 590 nm; 2.22 eV), Bi 4 TeO 4 F 4 (TeO 3 ) 2 (SeO 3 ) 2 (0.20 at 1064 nm; 2.74 eV), and HgTeO 2 F­(OH) (0.09 at 1064 nm; 3.26 eV) . However, many of the reported tellurites exhibit small band gaps, which greatly hamper their availability in the field of birefringent materials. , In order to improve the band gap of tellurite birefringent materials, the researchers have attempted the following and made progress: (1) introducing tetrahedral anionic groups with a wide transmission range, − such as Y 2 (Te 4 O 10 )­(SO 4 ) (0.124 at 1064 nm; 4.1 eV) and Ba 2 TeP 2 O 9 (0.126 at 1064 nm; 4.28 eV), (2) introducing the strongest electronegative F element, − such as BaF 2 TeF 2 (OH) 2 (0.078 at 300–700 nm; 5.9 eV) and Li 7 (TeO 3 ) 3 F (0.097 at 1064 nm; 4.75 eV), and (3) introducing planar triangular groups, , such as LaTeBO 5 (0.083 at 532 nm; 4.2 eV) …”