RbBiP₂S₆: A Promising IR Nonlinear Optical Material with a Giant Second-Harmonic Generation Response Designed by Aliovalent Substitution

Abstract

Non-centrosymmetric (NCS) Bi-based oxides with giant second-harmonic generation (SHG) responses have been widely studied as UV–visible nonlinear optical (NLO) materials over the past few decades. However, high-performance Bi-based NLO chalcogenides in the infrared (IR) region have rarely been reported. Herein, a novel NCS Bi-based thiophosphate RbBiP2S6 (P21) has been successfully designed by the aliovalent substitution of centrosymmetric Rb4P2S6 (P21/c). Notably, this compound affords a record-high SHG intensity (11.9 × AgGaS2 @ 2.05 μm) ever reported for IR-NLO sulfides. Moreover, detailed structure analysis and theoretical studies indicate that the superior IR-NLO performance can be attributed to the highly polarizable [BiS7] units together with the favorable alignment of ethane-like [P2S6] units. This discovery offers an excellent candidate for IR-NLO applications and suggests that aliovalent substitution is a promising way to search for unknown high-performance NLO materials.

Oxychalcogenides as Promising Ultraviolet Nonlinear Optical Candidates: Experimental and Theoretical Studies of AEGeOS2(AE = Sr and Ba)

“…The d 14 values at 1064 nm (ca.1.17 eV) were calculated to be 1.87, 1.65, and 0.96 pm/V for SrGeOS 2 , BaGeOS 2 , and KDP, respectively (Figure a). This result is obviously inconsistent with the experimental fact that SrGeOS 2 has a smaller SHG coefficient compared to BaGeOS 2 (Figure ); similar phenomena can also be found in other materials. − The theoretical birefringence (Δ n ) of AEGeOS 2 (AE = Sr and Ba) at 1064 nm are 0.121–0.135 (Figure b), which are larger than the KDP (0.034@1064 nm) and beneficial to realize PM in the UV region. Meanwhile, the calculation results show that both of the two compounds still have large enough birefringence (0.117–0.131) at 2050 nm to achieve PM and greater than AgGaS 2 (0.039@2050 nm).…”

Phase matching achieved by isomorphous substitution in IR nonlinear optical material Ba2SnSSi2O7with an undiscovered [SnO4S] functional motif

“…Hence, the LIDT value of Ba 2 SnSSi 2 O 7 at 1064 nm was also evaluated by a single-pulse measurement technology, 55 and AgGaS 2 and KDP were employed as the standards. The LIDT value was measured to be 75.29 MW cm À2 , which is close to 26.7 and 1.9 times those of AgGaS 2 (2.82 MW cm À2 ) [56][57][58][59][60] and KDP (39.8 MW cm À2 ), 61 respectively. Besides, the birefringence (Dn) was performed via a ZEISS Axio A1 polarizing microscope.…”

The exploration of new infrared nonlinear optical crystals based on the polymorphism of BaGa4S7

“…On the other hand, the flexible coordination of alkali or alkali-earth cations is also helpful for adjusting the orientation of microscopic dipole moments of the chalcogenide MQ 4 (M = Zn, Cd, Ga, In, Si, and Ge; Q = S, Se) tetrahedra to make them have the additive manner and enhance the SHG responses. 20,21 Under the guidance of these ideas, lots of high-performance IR chalcogenide NLO crystals have been synthesized, including BaGa 4 Q 7 (Q = S, Se), 22,23 BaGa 2 GeQ 6 (Q = S, Se), 24 LiGaQ 2 (Q = S, Se), 25,26 Na 2 BaMQ 4 (M = Ge, Sn; Q = S, Se), 27 Li 2 Ga 2 GeQ 6 (Q = S, Se), 28 etc. † Electronic supplementary information (ESI) available: Atomic coordinates, equivalent isotropic displacement parameters, and the bond valence sums of each atom; selected bond distances and angles; experimental and calculated XRD patterns; elemental analysis; IR transmission; dipole moment calculations.…”

“…On the other hand, the flexible coordination of alkali or alkali-earth cations is also helpful for adjusting the orientation of microscopic dipole moments of the chalcogenide MQ 4 (M = Zn, Cd, Ga, In, Si, and Ge; Q = S, Se) tetrahedra to make them have the additive manner and enhance the SHG responses. 20,21 Under the guidance of these ideas, lots of high-performance IR chalcogenide NLO crystals have been synthesized, including BaGa 4 Q 7 (Q = S, Se), 22,23 BaGa 2 GeQ 6 (Q = S, Se), 24 LiGaQ 2 (Q = S, Se), 25,26 Na 2 BaMQ 4 (M = Ge, Sn; Q = S, Se), 27 Li 2 Ga 2 GeQ 6 (Q = S, Se), 28 etc .…”