Rare earth cerium doping effects in nonlinear optical materials: potassiumhydrogen phthalate (KHP) and tris(thiourea)zinc(II) sulfate (ZTS)

The influence of Ce(IV) doping on ZTS and KHP crystals over a concentration range from 1 to 10 mol% in the solution during crystallization, which leads to a true concentration range from few ppm to few tens of ppm in the crystals has been investigated. The XRD and FT-IR analyses indicate that the crystal undergoes considerable stress as a result of doping. Incorporation of the Ce(IV) dopant into the crystal lattice was well confirmed by energy dispersive X-ray spectroscopy (EDS) and quantified by inductively coupled plasma (ICP) technique. The high-resolution X-ray diffraction (HRXRD) studies reveal that Ce doping in KHP leads to degradation of crystal quality whereas ZTS can accommodate Ce predominantly at the substitutional sites without any degradation of crystalline perfection. The second harmonic generation (SHG) efficiency is not influenced by Ce doping in the KHP crystals while in ZTS crystals, it is enhanced to a considerable extent correlated with moderately improved crystalline perfection.