Enhancement in ferroelectric, pyroelectric and photoluminescence properties in dye doped TGS crystals

Pure and dye doped (0.1 and 0.2mol%) Triglycine Sulfate (TGS) single crystals were grown by slow evaporation technique. A pyramidal coloring pattern, along with XRD and FT-IR studies confirmed the dye doping. Decrease in dielectric constant and increase in Curie temperature (Tc) were observed with increasing doping concentration. Low absorption cut off (231nm) and high optical transparency (>90%) resulting in large band gap was observed in UV–VIS studies. In addition, strong hyper-luminescent emission bands at 350 and 375nm were observed in which the relative intensity were found to be reversed as a result of doping. In P–E hysteresis loop studies, a higher curie temperature and an improved and more uniform figure of merit over a large region of the ferroelectric phase were observed. The improved dielectric, optical and ferroelectric/pyroelectric properties make the dye doped TGS crystals better candidate for various opto- and piezo-electronics applications. Dye doping in TGS crystal resulted in hourglass morphology, increased hyper-luminescence intensity, improved Tc and figure of merit. [Display omitted] ► Amaranth dye doping in TGS crystals resulted in hourglass morphology. ► Doping resulted in enhancement of Curie temperature from 49 to 53°C. ► Low cut off (230nm) and wider transmittance window observed. ► Strong hyper-luminescent emission bands at 350 and 375nm were observed. ► High and uniform figure of merit in ferroelectric phase was obtained