Anionic Aliovalent Substitution from Structure Models of ZnS: Novel Defect Diamond‐like Halopnictide Infrared Nonlinear Optical Materials with Wide Band Gaps and Large SHG Effects

Abstract

To design pnictide nonlinear optical materials with wide band gap and large second‐harmonic generation, the heavy halogen I was introduced into pnictides through anionic aliovalent substitution with diamond‐like ZnS as templates. Thus, four excellent halopnictide‐based infrared nonlinear optical crystals, MII3PnI3 (MII=Zn, Cd; Pn=P, As), were obtained. They all exhibited defect diamond‐like structures with highly parallel‐oriented [MIIPnI3] mixed‐anionic tetrahedral groups, leading to excellent physical properties including wide band gaps (2.38–2.85 eV), large second harmonic generation responses (2.7–5.1×AgGaS2), high laser‐induced damage thresholds (5.5–10.7×AgGaS2), and good IR transparency. In particular, Cd3PI3 and Cd3AsI3 achieved phase‐matching (Δn=0.035 and 0.031) that their template β‐ZnS could not do. Anionic aliovalent substitution provides a feasible strategy to design novel promising halopnictide IR NLO materials.

Heteroanionic Melilite Oxysulfide: A Promising Infrared Nonlinear Optical Candidate with a Strong Second-Harmonic Generation Response, Sufficient Birefringence, and Wide Bandgap

“…This anion-mixing strategy has been applied to regulate the NLO performance in several ultraviolet (UV) NLO material systems functioned by BO x F 4– x , PO x F 4– x , PO x S 4– x , [NH 2 SO 3 ] − , [SO 2 (NH 2 ) 2 ], and SiO x N 4– x groups. However, the general significance of this strategy to optimize the performances of IR-NLO analogues has not been clarified yet due to the lack of a suitable material system with adjustable anionic compositions. − …”

A zinc-conducting chalcogenide electrolyte

“…Therefore, Vac Zn are formed to balance the charge distribution. The aliovalent anion substitution would not only change the lattice structure due to variant dopant sizes but also influence the electronic structure by tuning electron densities around anions and vacancies ( 28 ).…”

Halide-Induced Band Gap Enhancement from Ba2SnSe4 to KBa2SnSe4Cl

“…The band engineering strategy is widely used to regulate the band gap to meet the different application needs for target compounds. − Generally speaking, the band engineering strategy in the inorganic material synthesis field mainly includes a cationic regulation strategy (CRS) − and anionic regulation strategy (ARS), − while both CRS and ACS contain isovalent substitution − and aliovalent substitution − completely or incompletely. For example, Pb 2 GaF 2 (SeO 3 ) 2 Cl and BiFSeO 3 with a larger second harmonic generation can be obtained by replacing (NbO 2 ) + in Pb 2 NbO 2 (SeO 3 ) 2 Cl and (IO) 3+ in BiOIO 3 with (GaF 2 ) + and (SeF) 3+ , respectively.…”