Growth, structural, optical and microhardness study of KCl doped triglycine sulphate (TGS) crystals for photonic applications

Single crystals of pure triglycine sulphate (TGS) and KCl doped TGS were grown from aqueous solutions by slow evaporation technique. The concentrations of KCl in the TGS mother solution were varied from 0.2 to 1.0 mol%. The grown crystals were examined by energy dispersive X-ray (EDX) to find out the presence of doping elements in the crystals. The presence of functional groups in the grown crystals was identified by Fourier Transform Infrared Spectroscopy. The lattice parameters were determined by powder X-ray diffraction and reveals that the crystals are belong to monoclinic structure. The UV-visible transmittance spectra were carried out on the grown crystals. A sharp fall in the optical transmittance is observed at 240 nm for pure TGS and all KCl doped TGS crystals and there is no shift of the lower cut off wavelength value. The optical band gap of TGS is found to be 5.0 eV. The mechanical strength of the grown crystal has been analyzed by Vickers microhardness measurement.