Noncentrosymmetric Tetrel Pnictides RuSi₄P₄ and IrSi₃P₃: Nonlinear Optical Materials with Outstanding Laser Damage Threshold

Abstract

Noncentrosymmetric (NCS) tetrel pnictides have recently generated interest as nonlinear optical (NLO) materials due to their second harmonic generation (SHG) activity and large laser damage threshold (LDT). Herein nonmetal‐rich silicon phosphides RuSi4P4 and IrSi3P3 are synthesized and characterized. Their crystal structures are reinvestigated using single crystal X‐ray diffraction and 29Si and 31P magic angle spinning NMR. In agreement with previous report RuSi4P4 crystallizes in NCS space group P1, while IrSi3P3 is found to crystallize in NCS space group Cm, in contrast with the previously reported space group C2. A combination of DFT calculations and diffuse reflectance measurements reveals RuSi4P4 and IrSi3P3 to be wide bandgap (Eg) semiconductors, Eg = 1.9 and 1.8 eV, respectively. RuSi4P4 and IrSi3P3 outperform the current state‐of‐the‐art infrared SHG material, AgGaS2, both in SHG activity and laser inducer damage threshold. Due to the combination of high thermal stabilities (up to 1373 K), wide bandgaps (≈2 eV), NCS crystal structures, strong SHG responses, and large LDT values, RuSi4P4 and IrSi3P3 are promising candidates for longer wavelength NLO materials.

Synthesis-enabled exploration of chiral and polar multivalent quaternary sulfides

“…The obtained non-linear optical properties are comparable to other TM-free studied analogues in this family, ×0.5–1.8 SHG and ×2.5–6 LDT as compared to those for AgGaS 2 : La 6 Li 2 Ge 2 S 14 , La 6 Li 2 Sn 2 S 14 , 56 Sm 6 Li 2 Si 2 S 14 , 28 La 6 Sb 0.66 Si 2 S 14 , 14 La 6 Ga 2 GeS 14 , 27 and La 6 In 2 GeS 14 ; 27 as well as other sulfides (Li 2 ZnGeS 4 , 95 Li 2 MnGeS 4 , 96 Na 2 Hg 3 M 2 S 8 (ref. 97 )) and pnictides (RuSi 4 P 4 and IrSi 3 P 3 , 9 MgSiAs 2 , 98 Ba 2 Si 3 P 6 , 99 and MnSiP 2 (ref. 100 )).…”

“…This can be achieved through the atomic mixing of components to achieve homogenous precursor reactants. We have demonstrated this approach for several ternary metal pnictides, where a metal-tetrel precursor (e.g., LaSi) was made by arc-melting and reacted with a volatile pnictogen (P or As) at synthetic temperatures of 600-1050 o C, forming stoichiometric products such as: LaSiP3 6 , La2SiP4 7 , AuSiAs 8 , RuSi4P4, and IrSi3P3 9 .…”

“…, LaSi) was made by arc-melting and reacted with a volatile pnictogen (P or As) at synthetic temperatures of 600–1050 °C, forming stoichiometric products such as: LaSiP 3 , 6 La 2 SiP 4 , 7 AuSiAs, 8 RuSi 4 P 4 , and IrSi 3 P 3 . 9 …”

The Rise of Infrared Nonlinear Optical Pnictides: Advances and Outlooks

“…Although two novel nonmetal‐rich silicon phosphides, namely, RuSi 4 P 4 and IrSi 3 P 3 , were obtained in 1995 by Madar et al., [60,61] their IR‐NLO properties were reported by Kovnir and co‐workers until 2021 [46] . Notable, current RuSi 4 P 4 possesses the same non‐centrosymmetric space group P 1 (No.…”

“…But over the past few decades, most of the research in this field is concentrated in the non‐centrosymmetric metal chalcogenides, [6] which results in many IR‐NLO chalcogenides with excellent comprehensive properties, such as BaGa 4 S 7 , [7] BaGa 4 Se 7 , [8] SnGa 4 S 7 , [9] Sn 2 Ga 2 S 5 , [10] Hg 3 P 2 S 8 , [11] γ‐NaAsSe 2 , [12] Li 2 CdGeS 4 , [13] α‐Li 2 ZnGeS 4 , [14] La 4 InSbS 9 , [15] Na 2 ZnGe 2 S 6 , [16] CsGa 2 SnSe 6 , [17] Li 2 ZnSiS 4 , [18] Li 2 BaGeS 4 , [19] CuHgPS 4 , [20] BaHgGeSe 4 , [21] Sr 5 ZnGa 6 S 15 , [22] [Li 2 Cs 2 Cl][Ga 3 S 6 ], [23] [Rb 3 Br][PGa 3 S 8 ], [24] [CsBa 2 Cl][Ga 4 S 8 ], [25] [Ba 4 Cl 2 ][ZnGa 4 S 10 ] [26] and so on and so forth. Compared with a large number of research results in IR‐NLO chalcogenides, only a few IR‐NLO pnictides are discovered in this area [28–61] and the major research works are still focused on classical binary or ternary semiconductors, such as GaAs, [27] ZnGeP 2 , [5] CdSiP 2 [7] and CdGeAs 2 [29] . Generally, pnictides exhibit small band gaps (E g <2.5 eV) and are difficult to synthesize, which limit their development in the IR‐NLO field.…”