Aplicação de titanatos de alcalinos terrosos em células solares de estado sólido

Abstract

Commonly, dye-sensitized solar cells (DSSCs) are characterized by three basic components: an electrode, consisting of a layer of some semiconductor oxide associated with a dye; an electrolyte, which performs the function of oxidation in the system; and a counter electrode, usually platinum, which acts as a catalytic agent. The individual investigation of each of these components is the subject of several studies, since the results show an increase or decrease in the obtained values of short circuit current and open circuit potential. These parameters are essential for estimating the calculation of the conversion efficiency of solar energy into electric energy. The class of perovskite-like materials has gained ground in studies involving dye-sensitized solar cells when used as an electrode in this type of device. Therefore, the aim of this work was to construct DSSCs solar cells by exploring the electrode composition with perovskite oxides and the need for their dye sensitization. As a starting point, Barium Titanate and Calcium Titanate powders were synthesized through the microwave assisted hydrothermalization method, in which the influence of two different Titanium precursors was evaluated. According to the structural, morphological and optical properties, solutions were prepared with the particles of Barium Titanate, synthesized with Titanium isopropoxide. Among these properties, stands out the low recombination rate of the electron-hole pair, evidenced by the photoluminescent emission spectrum. The solutions were deposited by using the doctor blade technique on FTO (Fluorine-doped tin oxide) substrates, which is a conductive substrate with a thin layer of SnO2/F. Five solar cells were made, in which two electrodes were sensitized by a ruthenium N-3 dye. The components complementation, two electrolytes with cations (Li and K), and different concentrations were tested to work in the process of oxidation of the species, and the counter electrode was prepared with a layer of platinum deposited by the thermal decomposition method.