Investigação estrutural e morfológica do sistema Zirconato Férrico de Bário para aplicação em células solares.

Abstract

The digital revolution, also known as the third industrial revolution, which is occurring in the last decades, is directly linked to the development and improvement of materials. In this context, the class of materials with a perovskite structure has stood out, specially in the area of photovoltaic devices. The Barium Zirconate (BZO) is a compound that belong to the perovskite group which recently has received much attention due to its excellent thermal properties. Moreover, the insertion of dopant ions in the perovoskite structure can change its properties, possibly enhancing them. For these reasons, investigations that aim to evaluate the performance of dopant elements in these compounds are a commonplace. However, there are still a vast number of chemical combinations to be studied, such as the Iron Barium Zirconate (BZFO) wich, up until this moment, is little addressed in the literature. Based on these factors, this work has as one its main purposes to analyze how the Fe addition and the synthesis by Microwave Assisted Hydrotermal (MAH) method alter BZO properties. Therefore, six (6) samples of the BaZr1􀀀2xFe2xO3􀀀 were synthesized, and then characterized using the X-Ray Diffraction (XRD), MEV, Raman Spectroscopy e UV-Vis techniques. All the BZFO samples present a crystalline structure indexed as the BZO cubic phase with structural distortions caused by the Fe addition in the crystalline matrix. Besides that, the estimated band gap values are drastically diminished with the solid solution, emphasizing new applications for the compound. For this reason, the present investigation also explored the utilization of these compounds acting as photoelectrodes in third generation solar cells. Photovoltaic devices using the BZO and BZFO samples were fabricated, and to evaluate the performance of these solar cells, J-V curves were analyzed. In the measurements performed, all the samples presented photovoltaic response but, unexpectedly, the sample with lower Iron concentration stood out, even though its band gap is considered too high for this application (4,9 eV).