Comparative structural, linear-non-linear optical, laser damage threshold, dielectric and thermal analysis of pristine and L-cysteine influenced KH2PO4 crystal for NLO applications

•Large size crystals of LC-KDP are grown by low cost technique.•Structural and vibrational studies confirm the growth of LC-KDP crystals.•LC enhanced the optical transparency of KDP crystal by 8%•Enhanced SHG of LC doped KDP crystal is 1.84 times higher than KDP.•Thermal stability of the grown crystal has been studied.