Optical properties of a new binary lead-free ferroelectric semiconductor Bi1/2Na1/2TiO3–Nd1/2Na1/2TiO3 solid solution system

A new solid solution system of binary (1-x)Bi1/2Na1/2TiO3 + xNd1/2Na1/2TiO3 compound was well synthesized by a chemical method. The structural studies by X-ray diffraction and Raman scattering techniques provided strong evidence for the complex incorporation of Nd3+ cations into the host Bi1/2Na1/2TiO3 crystal during the formation of solid solutions. The random substitution of Nd3+ cations at both A- and B-sites of the host Bi1/2Na1/2TiO3 crystal resulted in reducing the optical bandgap from 3.05 to 2.94 eV. The strong photoemission intensity in the near-infrared region, around 883–915 nm, was obtained at room temperature, which was related to electron transitions from 4F3/2 to 4I9/2 levels of Nd3+ cations. The observation in near-infrared photoemission of the new binary Nd1/2Na1/2TiO3-modified Bi1/2Na1/2TiO3 materials exhibited a new method successfully applied for the integration of photoluminescence in lead-free ferroelectric materials for further smart electronic device applications.