Potassium dihydrogen phosphate (KDP)Admixturedtriglycinesulphate (TGS) single crystal (KDPTGS) with concentration of KDP in the growth solutions varied from 10mole% to50mole% has been grown by the slow evaporation technique. Crystal structure was studied by x-ray powder diffraction. KDPTGS crystallizes in the monoclinc system with P21/c space group.X-ray analysis showed a slight variation in the lattice parameters for admixtured crystals. The absorption spectra for pure and KDP doped TGS crystals have significantly low cut-off wavelengths and good transmittances towards the visible and infrared regions. By increasing KDP concentration, the optical transmittance increases, however the cut-off shifts to lower wavelengths. The optical data are analyzed and interpreted in terms of allowed indirect transitions. The optical energy gap (Eg) has the value of 4.912eVfor pure TGS crystal. This value increases with increasing KDP concentration and tends to saturate ata doping concentration of 30mole% KDP. The modes of vibration of different functional groups present in the grown crystals were identified by the FTIR spectral analysis.
