Mg2In3Si2P7: A Quaternary Diamond-like Phosphide Infrared Nonlinear Optical Material Derived from ZnGeP2

Balancing the second-harmonic generation (SHG) coefficient, band gap, and birefringence is a vital but addressable challenge for designing infrared nonlinear optical materials. By applying a rigidity-flexibility coupling strategy, a quaternary diamond-like phosphide, Mg2In3Si2P7, with wurtzite-type superstructure was successfully designed and synthesized. Remarkably, it achieved the rare coexistence of giant second-harmonic generation (2 x ZnGeP2 and 7.1 x AgGaS2), suitable band gap (2.21 eV), moderate birefringence (0.107), and wide IR transparent range (0.56-16.4 mu m). First-principles calculations revealed that the giant SHG response and large birefringence can be attributed to the synergy of arrangement-aligned [InP4] and [SiP4] tetrahedra. This work not only opens a new avenue for designing advanced infrared nonlinear optical materials but also may spur more explorations on quaternary diamond-like pnictides.

Automated summary

By applying a rigidity-flexibility coupling strategy, a quaternary diamond-like phosphide, Mg2In3Si2P7, was designed and synthesized successfully, achieving the rare coexistence of giant second-harmonic generation, suitable band gap, moderate birefringence, and wide IR transparent range. This work not only opens a new avenue for designing advanced infrared nonlinear optical materials but also may spur more explorations on quaternary diamond-like pnictides.