Spectral, optical and dielectric analyses on L-lysine p-nitrophenolate monohydrate organic crystals

Organic crystal, L-lysine p-nitrophenolate monohydrate (LLPNP) has been grown from an aqueous solution by the slow evaporation method. The lattice parameters and space group of the grown crystal were determined from powder X-ray diffraction (PXRD). The external and internal vibrational analyses of the crystal were carried out using the factor group method. The predicted vibrations were experimentally verified using FT-IR and FT-Raman spectra. The dielectric behaviour of the crystal revealed that higher the frequency of charge carriers, lesser the activation energy. From the optical studies it is noted that, the lower cut off wavelength occurs at 460 nm and the band gap was found to be 2.78 eV. The second harmonic generation (SHG) intensity of the title crystal was measured by Kurtz–Perry powder method and found to be as 1.45 times as that of KDP. The crystal was found to exhibit positive photoconductivity.