Effect of amino acid dopants on the spectral, optical, mechanical and thermal properties of potassium acid phthalate crystals for possible optoelectronic and frequency doubling applications

•The growth of amino acid doped KAP crystals was achieved by SEST.•High optical transparency was observed inl-Valine doped KAP crystal.•Load dependent hardness parameters were calculated from mechanical studies.•Amino acid doped KAP crystals exhibits phase matching property.

Undoped and amino acid (l-Arginine and l-Valine) doped KAP crystals were grown by slow evaporation solution growth technique. The changes in the structural, spectral, optical, mechanical and thermal properties were observed. The sharp prominent peaks in the indexed powder XRD pattern confirms the crystalline nature of the sample. Optical studies reveal that the crystal is transparent in the entire visible light region. Thermal stability was checked by TG/DTA analysis. The mechanical stability was evaluated from Vicker’s microhardness test. The SHG efficiency for the title materials was tested with different particle sizes by the Kurtz and Perry powder method, which established the existence of phase matching.