Semiconducting Properties and Phase-Matching Nonlinear Optical Response of the One-Dimensional Selenophosphates ANb₂PSe₁₀ (A = K, Rb, and Cs)

Abstract

The new compounds ANb 2 PSe 10 , where A = K, Rb and Cs, form from polyselenophosphate flux reactions and crystallize in the noncentrosymmetric space group Pc. They feature infinite one-dimensional 1 / ∞ [Nb 2 PSe 10 -] chains separated by alkali cations. The chains consist of [Nb 2 (Se 2 ) 2 ] 4+ clusters bridged by a diselenide and a [PSe 4 ] 3-group. The chains pack differently depending on which alkali cation is present in the lattice. As a result, the analogs are not isostructural with respect to each other, and each has a different unit cell. The reaction

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

“…In chalcogenides, the typical NCS chromophores encompass [MQ 4 ] n − (M = Ag, Zn, Ga, Ge, P, etc. ; 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).…”

A2SrMIVS4 (A = Li, Na; MIV = Ge, Sn) concurrently exhibiting wide bandgaps and good nonlinear optical responses as new potential infrared nonlinear optical materials

“…After decades of exploration and development, hundreds of IR NLO materials have been synthesized and note that chalcogenides are the main research source for the exploration of new IR NLO materials 8. The previously reported results show that by incorporation of the second-order Jahn–Teller (SOJT) effect d 0 transition-metals or/and lone-pair cations into crystal structures it is hard to obtain suitable balanced performances for IR NLO materials 9. Thus, an efficient design strategy that could enhance the E g and simultaneously maintain good d ij appears to be particularly important.…”

Non‐centrosymmetric Selenides AZn4In5Se12 (A=Rb, Cs): Synthesis, Characterization and Nonlinear Optical Properties

“…A crystallographic non‐centrosymmetric (NCS) structure is the prerequisite condition of an NLO material. Over the past decades, numerous strategies have been introduced to design new NCS materials, and many MFIR NLO compounds with strong powder SHG responses have been discovered and prepared . Among them, construction of diamond‐like frameworks (DLFs) has been considered as one of the most effective methods to obtain new MFIR NLO materials with excellent properties; typical examples include BaGa 4 Q 7 (Q=S, Se), Ba 3 AGa 5 Se 10 Cl 2 (A=K‐Cs), PbGa 4 S 7 , Li 2 CdGeS 4 , and BaGa 2 MQ 6 (M=Si, Ge, Sn; Q=S, Se) …”