Pure and 0.1 mol% amaranth dye doped zinc tris-thiourea sulphate (ZTS) crystals were grown by slow evaporation technique. Orthorhombic structures with changed morphology were observed. Various functional groups present were identified by FTIR and Raman analysis. UV-Vis spectra shows wide transmittance and increased optical band gap from 4.54 to 4.59 eV, with lower extinction coefficient in doped case. In photoluminescence measurement, an intense peak at 416 nm was observed for doped ZTS. Dielectric constant value increases from 3.28 to 9.40 at 1 kHz with doping. Piezoelectric coefficient d(33) is also enhanced from 0.24 to 3 pC/N. (C) 2013 Elsevier B.V. All rights reserved.