Speaker
Description
The search for low-cost technologies that reduces our energy consumption is a priority in our struggle for the well-being of our environment. The BaTiO3 particles were synthesized for this research with the aim of enabling a more efficient use of the electric energy in electroluminescent devices (ELDs). In these devices, BaTiO3 is often used as the dielectric layer. A more efficient dielectric layer would allow a reduction of the thickness of the overall device, which would result in lower production costs and increased brightness. The BaTiO3 was synthesized using a sol-gel method, which allows for the control of particle size and dopant concentration. The material was characterized using scanning electron microscopy, X-ray diffraction analysis and X-Ray photoelectron spectroscopy (XPS). The XPS results showed a large split in the lanthanum's binding energy which was never discussed in the literature. Following this, a hypothesis was advanced about the interaction between the Ti-O strong bond and the lanthanum. The ELDs were screen-printed using inks made from the experimental BaTiO3 and a ZnS commercial powder. The optimal concentration of dopant (0,5 mol% La) was obtained by using impedance spectroscopy and photometry to determine the electric permittivity of the BaTiO3 layer and the luminescence of the ELDs, respectively. The samples made with this concentration exhibited a luminescence more than double the one emitted by samples made with commercial powders of both BaTiO3 and ZnS. Even more remarkably, one of the luminescent samples was found to be 600% brighter than the others. Although these are preliminary results, they could prove to be of great importance for the field of ELD research, provided a verifiable reproducibility with a commercial printer.
