Aminopyridines and 4-nitrophenol cocrystals for terahertz application

Co-crystals series of different mono- and diaminopyridines non-centrosymmetric complexes, namely 3,4-diaminopyridine-4-nitrophenol-4-nitrophenolate, 2,6-diaminopyridine-4-nitrophenol-4-nitrophenolate and 2-aminopyridine-4-nitrophenol-4-nitrophenolate were grown by slow solvent evaporation from solution with constant temperature technique. Terahertz absorption and refraction properties of the materials were measured, and the co-crystals were tested as generators of THz pulses under irradiation with 800 nm Ti:Sapphire femtosecond laser. Efficiency of the optical-to-THz conversion was compared to that of ZnTe crystal.