Zn₃P₂S₈: A Promising Infrared Nonlinear-Optical Material with Excellent Overall Properties

Abstract

The thiophosphate ZnPS is reported for its potential application in infrared (IR) nonlinear optics. This nondeliquescent compound features a cubic closet packing of the (PS) groups, with Zn filling in three-quarters of the tetrahedral interspaces. The optical band gap of ZnPS is characterized as 3.12 eV, which is very beneficial to improving the laser damage threshold. Besides, ZnPS demonstrates good phase matchability (PM) with a strong second-harmonic-generation (SHG) response that is about 2.6 times that of AgGaS, achieving a valuable balance among good phase matchability, strong SHG response, and large optical band gap. The origin of these attractive optical properties is investigated in detail via theoretical calculations. Moreover, the differential scanning calorimetry curve indicates a congruent-melting thermal behavior of ZnPS, which is conducive to large single-crystal growth. The excellent comprehensive performance of ZnPS makes it a practically usable IR nonlinear-optical candidate.

Structural modification from centrosymmetric Rb4Hg2Ge2S8 to noncentrosymmetric (Na3Rb)Hg2Ge2S8: mixed alkali metals strategy for infrared nonlinear optical material design

“…; Q = chalcogen), 9–13 trigonal-planar p-conjugated groups (AgQ 3 , HgQ 3 ), 14,15 d 0 -second-order Jahn–Teller-effect cations (Ti 4+ , Nb 5+ ), 16 and ns 2 -electron cations (Pb 2+ , As 3+ ). 17 Under the guidance of these ideas, high-performance IR NLO materials with tetrahedron [MQ 4 ] n − as the NLO functional motif have been extensively studied, such as BaGa 4 Q 7 (Q = S, Se), 18,19 BaGa 2 MQ 6 (M = Si, Ge; Q = S, Se), 20 M II 3 P 2 S 8 (M II = Zn, Hg), 21,22 and AM II M IV Q 4 (A = Eu, Sr, Ba; M II = Mn, Zn, Cd, Hg; M IV = Si, Ge, Sn; Q = S, Se). 23–28 A common strategy for broadening band gaps is introducing alkali or alkaline earth metals to these compounds.…”

EuHgGeSe4 and EuHgSnS4: Two Quaternary Eu-Based Infrared Nonlinear Optical Materials with Strong Second-Harmonic-Generation Responses

“…Highly polarizable cations (e.g., d 10 configuration Zn 2+ ) are always selected to introduce into crystal structures to enhance the SHG effect of metal chalcogenides to maintain a large optical band gap, as demonstrated by Na 2 ZnGeS 4 (d ij = 1× that of AGS, E g = 3.25 eV), 16 Zn3P2S8 (d ij = 2.6× that of AGS, E g = 3.12 eV), 17 Li 2 ZnSiS 4 (d ij = 1.2× that of AGS, E g = 3.90 eV), 18 and CuZnPS 4 (d ij = 3× that of AGS, E g = 3.0 eV). 19 In comparison with Zn 2+ , Hg 2+ cation not only contains a 18e electronic configuration but also a much higher polarizable and deformable electron cloud, which could markedly be favorable to the SHG effect.…”

[ABa2Cl][Ga4S8] (A = Rb, Cs): Wide-Spectrum Nonlinear Optical Materials Obtained by Polycation-Substitution-Induced Nonlinear Optical (NLO)-Functional Motif Ordering

“…), − and tetrahedral blocks (MQ 4 ) n − (M = Zn, Ga, Ge, etc. ; Q = S, Se). − These acentric anionic motifs were frequently assembled into NCS structures with other cations. However, when incorporating strongly electropositive cations (alkali metal, alkaline-earth metal, or rare-earth metal), which usually form directionless ionic bonding interactions, acentric anionic motifs could be packed centrosymmetrically. , Another simple but effective strategy is transforming a parent centrosymmetric (CS) structure to an NCS one through structure modification methods, which shares the benefit of inheriting the NLO-functional motifs from the parent CS compounds in the target NCS ones.…”