Pure triglycine sulphate (TGS) and LiSO4-doped TGS crystals were grown from aqueous solution by natural evaporation method. The grown crystals were characterized by UV-vis spectroscopy, electrical conductivity ( ) measurement, dielectric studies, microhardness, and thermogravimetry/differential thermal analysis. Pure TGS and LiSO4-doped TGS crystals were found highly transparent and full faced. The direct current conductivity is found to increase with temperature as well as dopant concentrations. Curie temperature remains the same for pure and doped crystals, but dielectric constant and dielectric loss increase with dopant concentration. The Vicker’s microhardness of the LiSO4-doped TGS crystals along (001) face is found higher than that of pure TGS crystals. Etching studies illustrate the quality of the doped crystal. The experimental results evidence the suitability of the grown crystal for optoelectronic applications. 1. Introduction Triglycine sulphate, (NH2CH2COOH)3 H2SO4, crystal is considered as one of the potential materials for its wide range of applications, namely, UV tunable laser, second harmonic generation, and pyroelectric infrared sensors due to its high pyroelectric coefficient, optical transmission, and reasonably low dielectric constant [1–4]. It is a hydrogen-bonded ferroelectric crystal having a typical second-order phase transition at Curie temperature of 49°C [5–7]. TGS has a major disadvantage that it depolarized by thermal, mechanical, and electrical means. In order to overcome this difficulty, several studies have been attempted with different organic and inorganic dopants to achieve effective internal bias to stabilize the domains and desired pyroelectric and ferroelectric properties of TGS crystals [8–13]. Alkali halides such as NaBr and KBr-doped TGS crystals were grown, and the effects of the dopant have been investigated [14, 15]. Metal ion dopants have been added to modify the properties of TGS crystal [16, 17]. In the literature, only limited information is available about the behavior of TGS doped with Lithium [18]. Lithium reacts with water easily and noticeably with less energy than other alkali metals. Li+1 ion has 90？pm ionic radius, so it can easily reside into the lattice site of the TGS crystal and it can modify the electrical, mechanical, thermal, and surface morphology of TGS crystals. In the present work, LiSO4 is used as a dopant to see its effect on the property of TGS crystal. 2. Experimental Methods 2.1. Synthesis and Crystal Growth Analar Reagent (AR) grade glycine and concentrated sulphuric acid (H2SO4)
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