Seed supported solution growth and characterization of L-alanine single crystals for optoelectronics

The large growth of L-alanine single crystal (size = ~18 × 12 × 12 mm³) was achieved by seed supported solution growth technique for the first time. The structure and vibrational modes of the crystal were confirmed by X-ray diffraction (XRD) and FT-Raman analyses, respectively. UV–Vis-NIR absorbance and transmittance measurements were carried out and Tauc's rule is used to calculate energy gap for the grown crystal and found to be lie within 5.26–5.36 eV. The grown crystal is of high transparency between 80 and 89%, and the energy gap makes it useful for optoelectronic devices. The mechanical strength and chemical etching studies were also carried out and discussed. The present load independent hardness values along different faces of L-alanine crystal are noted ~30, 48, 50 and 65 kg/mm², respectively, which indicates that (2 0 2) face showing higher hardness value compare to all the faces. The etch pit density was observed to be ~4 × 10²/cm². Furthermore, dielectric and electrical studies were also done. The facile and low-cost growth, high optical transparency, energy gap, microhardness, dielectric and electrical of the grown crystal indicates that it is suitable for optoelectronic devices.