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

Pure and dye doped (0.1 and 0.2 mol%) 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 (T-c) were observed with increasing doping concentration. Low absorption cut off (231 nm) and high optical transparency (> 90%) resulting in large band gap was observed in UV-VIS studies. In addition, strong hyperluminescent emission bands at 350 and 375 nm 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. (C) 2012 Elsevier Inc. All rights reserved.