Phenol red dyed Bis thiourea Zinc acetate crystal growth and characterization for electro-optic applications

In current work, the growth of dyed Bis thiourea Zinc acetate single crystals of size ∼30 mm × 7 mm × 5 mm is achieved by solution technique. X-ray diffraction and FT-IR spectroscopy are used to verify crystal structure and functional groups. Intensity of diffraction peaks confirms good crystalline nature of dyed Bis thiourea Zinc acetate crystals than pure. Two absorption bands at ∼387 and 558 nm were observed in diffused reflectance spectra of dyed crystals. The energy gap was calculated for both crystals and establishes to be ∼4.87 eV for pure and ∼4.93 eV for dye crystals. Photoluminescence spectra were recorded and a green emission band was observed in dyed Bis thiourea Zinc acetate crystal at ∼513 nm was observed in dyed crystal. The grown crystals are found to be thermally stable up to 195 °C confirmed by differential scanning calorimetry. The value of dielectric permittivity is found to be reduced in dyed crystal. Microhardness of dyed crystals is much better than pure crystal. Surface study shows that the dyed crystals contain lesser defects than pure. Hence, the improved properties of dyed Bis thiourea Zinc acetate make it more useful than pure in electro-optic devices.