A₂SrM^IVS₄ (A = Li, Na; M^IV = Ge, Sn) concurrently exhibiting wide bandgaps and good nonlinear optical responses as new potential infrared nonlinear optical materials

Abstract

A series of A2SrMIVS4 compounds concurrently exhibiting wide bandgaps and good NLO responses were proven as promising IR NLO materials.

Synthesis, crystal structure, and electronic structure of Li2PbSiS4: a quaternary thiosilicate with a compressed chalcopyrite-like structure

“…For Li 2 PbSiS 4 , it can be seen that the lithium orbitals have nearly no involvement in the states near the Fermi energy, E F . This is in agreement with the calculated DOS for Li 2 SrSiS 4 (Yang et al, 2020), Li 2 SrGeS 4 , and Li 2 SrSnS 4 (Wu et al, 2019). On the other hand, when I = Cu or Ag in the I 2 -II-IV-VI 4 compounds, the Cu/Ag orbitals donate significantly to the states at the VB Max .…”

“…attributed to the IV-VI 4 units (Yang et al, 2020;Wu et al, 2017Wu et al, , 2019. We have generally observed that the Pb analogs tend to have narrower bandgaps in most cases where I = Li and Cu (Table 5).…”

“…For example, Cu 2 PbSiS 4 (Nhalil et al, 2018) has a tighter calculated bandgap than Cu 2 SrSiS 4 (Yang et al, 2020). Additionally, the calculated bandgaps of Li 2 PbGeS 4 (Aitken et al, 2001) and Li 2 SrGeS 4 (Wu et al, 2019) further illustrate this idea. It should be noted that while the calculated bandgaps for Ag 2 PbSiS 4 and Ag 2 BaSiS 4 are not in agreement with this noted tendency, the experimentally observed optical absorption edges support this concept (Sun et al, 2020).…”

“…Li 2 SrSiS 4 (I42m) has recently demonstrated excellent nonlinear optical (NLO) properties, with a second harmonic generation (SHG) response of $0.4Â AgGaS 2 and an outstanding laser-induced damage threshold (LIDT) of $21Â AgGaS 2 (Yang et al, 2020). Isostructural Li 2 SrGeS 4 and Li 2 SrSnS 4 (I42m) also give rise to worthy SHG responses and LIDTs that are better than that of the commercially available AgGaS 2 (Wu et al, 2019). Motivated by the above results and the long-known fact that chalcogenides (Chung & Kanatzidis, 2014; Aitken et al, 2014; Liang et al, 2017) and, in particular chalcopyrite-type materials, are excellent NLO materials (Ohmer & Pandey, 1998), we targeted Li 2 PbSiS 4 , which was conspicuously missing from the family.…”

LiMII(IO3)3 (MII=Zn and Cd): Two Promising Nonlinear Optical Crystals Derived from a Tunable Structure Model of α‐LiIO3

“…Recently, by considering the structure merits of the classical NLO materials, aliovalent substitution strategy has been proved to be an effective method to develop the NLO materials with improved properties . For example, many excellent deep‐ultraviolet or infrared (IR) NLO materials including Sr 2 Be 2 B 2 O 7 (SBBO), K 3 Ba 3 Li 2 Al 4 B 6 O 20 F, Li 2 ZnSiS 4 , and Li 2 SrGeS 4 have been structurally designed from the commercialized KBe 2 BO 3 F 2 (KBBF) or AgGaS 2 …”