Abstract
Nonlinear optical (NLO) crystals capable of expanding the spectral region of solid-state are of great importance for many high-tech applications, yet their rational structure design remains a great challenge because of the conflicting property requirements among second harmonic generation (SHG) response, ultraviolet (UV) cut-off edge, and birefringence. Herein, based on the chemical disubstitution of the classic NLO crystal Sr(2)Be(2)B(2)O(7) (SBBO), i.e., substituting [BO(3)] triangles with larger π-conjugated [B(3)O(7)] groups and substituting high-toxic [BeO(4)] tetrahedra with environment-friendly [AlO(4)] tetrahedra, a new high-performance aluminoborate NLO crystal, Ba(3)Al(2)B(12)O(24), has been successfully designed and synthesized. The theoretical calculations and optical property measurements indicate that Ba(3)Al(2)B(12)O(24) exhibits not only the largest SHG response among the reported aluminoborates (2.7 × KH(2)PO(4)), but also a short UV absorption edge (<190 nm) and moderate birefringence. More importantly, Ba(3)Al(2)B(12)O(24) melts congruently, and a single crystal with a size of 9 × 5 × 2 mm(3) has been grown by the top-seeded-solution-growth method. These demonstrate that Ba(3)Al(2)B(12)O(24) is a promising NLO crystal and the chemical disubstitution is a feasible strategy for the exploration of functional materials.