Optical, dielectric and surface studies on solution grown benzimidazole single crystals

Abstract Good quality single crystals of benzimidazole (BMZ) (4 × 5 × 6 mm3) have been successfully grown by solvent evaporation method using methanol as the solvent. The grown crystal belongs to orthorhombic system and the lattice constants were found from the powder X-ray diffraction analysis. The refractive index was determined at two different wavelengths by Brewster's angle method and found to be 1.607 and 1.613 respectively. The dielectric constant and dielectric loss of the crystal was studied as a function of frequency with different temperatures and the results are discussed. The optical band gap has been determined from the UV–Vis., analysis, and found that 4.1 eV. Such a wide band gap materials are useful for photonic and optoelectronic applications. The luminescence behavior has been examined in the wavelength region between 500–800 nm by using Ar+ ion laser as a source. The relative second harmonic generation (SHG) efficiency of the grown specimen is 4.5 times greater than that of the potassium dihydrogen phosphate (KDP) single crystal. Its phase matching angle has also been determined.