Melt growth of a new nonlinear optical organic crystal triethylphosphine sulfide using modified Bridgman-Stockbarger technique

Triethylphosphine sulfide, [C 2 H 5 ] 3 P(S) (abbreviated as TPS), seems to be a potential nonlinear optical organic material. Bulk single crystals of this material were grown using modified Bridgman-Stockbarger method. Commercially available triethylphosphine sulfide, procured from Johnson Matthey, was purified by physical vapor transport using low pressure sublimation (approximately 30 mTorr). The growth conditions are being optimized. The temperature gradient was chosen to be 6 - 8°C/cm, and the ampoule lowering rate was chosen to be 0.2 - 0.4 mm/hr and cooling rate after the crystal growth run was 5 - 10°C/day. Several TPS single crystals with size 10x10x15 mm 3 have been grown. The second harmonic generation was measured qualitatively and has been found to be comparable to phase matched potassium dihydrogen phosphate.