Achieving Combined Photoluminescence and SHG in a New Polar Hybrid Glass‐Ceramic with Square‐Pyramidal [SbBr ₅ ] Units

Abstract Hybrid glass‐ceramics have garnered extensive research interest due to their exceptional optical properties. Integrating luminescence and second harmonic generation (SHG) in hybrid glass‐ceramics is of particular interest for designing advanced devices, but is challenging owing to the lack of design principles. In this study, we present two textbook‐style comparative examples of hybrid antimony(III) bromides, (PPTPP) 2 [Sb 2 Br 8 ] ( 1 ) and (PPTPP) 2 [SbBr 5 ] ( 2 ), where PPTPP + = (3‐phenylpropyl)(triphenyl)phosphonium. Compound 1 with centrosymmetric seesaw [Sb 2 Br 8 ] dimers crystallizes in C 2/ c space group and is photoluminescently silent, whereas 2 with square‐pyramidal [SbBr 5 ] monomers crystallizes in polar P 2 1 space group and exhibits photoluminescence under excitation at 416 nm. Both 1 and 2 have higher thermostability with decomposition temperatures of 552 K, and undergo crystal‐liquid‐glass transitions upon heating and natural cooling, with melting temperatures of 445 and 484 K and vitrification temperatures of 331 and 340 K, respectively. Notably, the glassy sample of 2 exhibits an onset recrystallization temperature of 383 K, enabling the facile fabrication of a polar glass‐ceramic ( 2‐GC ) thin film under ambient conditions. Crucially, 2‐GC present the first example of a hybrid glass‐ceramic system integrating luminescence (centered at 691 nm) and SHG (12.8 times stronger than that of its polycrystalline counterpart), pioneering an innovative route for designing multichannel materials.