Investigations on growth, XRD, strain, FTIR, UV-Vis NIR, photoluminescence, SHG, and Z-scan analyses of L-cysteine picrate single crystal for NLO and optical limiting applications

Organic single crystal of L-cysteine picrate (LCP), an efficient NLO material for frequency conversion, opto-electronic, and optical limiting applications has been grown within 20 days by Slow Evaporation Solution Technique (SEST). PXRD analysis shows that the LCP is subjected to the noncentrosymmetric space group of P21 with a monoclinic crystal system. The very low strain value depicts that the level and dislocations of the defect in the lattice of LCP crystal are very low. The various functional group assignments were investigated by using Fourier-Transform Infrared (FTIR) spectrum analysis with the range of 4000-400 cm-1. The optical analysis (UV-Visible) confirmed that the crystal has a lower cut-off wavelength of 250 nm and very low absorption in the entire visible region. Photoluminescence (PL) spectrum analysis confirmed that the material exhibits blue emission and is suitable for LED device fabrication. The SHG efficiency for LCP crystal is established to be 1.7 times higher than KDP material. Z-scan measurement determined the LCP exhibits two-photon absorption-induced optical limiting action with a nonlinear absorption coefficient of 0.70 x 10-10 m/W and onset limiting threshold of 2.36 x 1012 W/m2 which indicates that it can be used in making laser protection gadgets.