Transparent KDP: ADP - 85:15 mixed crystals of enhanced size were grown by employing the conventional slow evaporation (C-KADP) as well as the Sankaranarayanan–Ramasamy (SR-KADP) method. High-resolution X-ray diffraction (HRXRD) analysis establishes a good crystalline quality for the SR-KADP crystal with a full width at the half maximum of 8 arc sec. The UV–Vis study shows an improved transmittance for the SR-KADP mixed crystal compared to the C-KADP mixed crystals. Less dislocation density and comparatively lower etch pits observed from the chemical etching study disclose a better quality of SR-KADP crystal over the C-KADP crystal. Photoconductivity analysis confirms a positive photo-conducting property for both the grown crystals. The observed two-fold increase in the value of d₃₃ (piezoelectric coefficient) for the SR-KADP crystal (4Pc/N) reveals an improved piezoelectric property. The laser damage threshold (LDT) of the SR-KADP crystal is 10.00 GW/cm² which declares the evidence for the higher damage threshold value compared to the C-KADP crystal (7.50 GW/cm²).