Síntese e caracterização de filmes de perovskita híbrida orgânica-inorgânica de MAPbI3 contendo pontos quânticos de PbS para aplicação em sistemas optoeletrônicos

Abstract

Solar energy is increasingly gaining prominence as a source of renewable and clean electricity. Research in photovoltaic systems has been stimulated to search for more efficient, inexpensive, and sustainable solar panels. Materials such as organic-inorganic hybrid perovskites and quantum dots (QDs) have drawn great attention for their easy processability, and interesting optical and electrical properties, which have soon achieved energy efficiencies of about 26%. Although great progress has been achieved in the efficiency of conversion of light energy into electricity in hybrid perovskite systems (organic-inorganic), there are still issues to be solved as; the stability of the material and defects of interfaces, so that these materials can be used in commercial systems. This work aimed to synthesize and characterize mapbi3 perovskite films, and MAPbI3 films with the insertion of PbS QDs at different concentrations and the application of these as active layers for application in photovoltaic devices. Optical characterizations such as absorption and photoluminescence (PL), as well as structural characterization with the use of scanning electron microscopy, X-ray diffraction, and dynamic light straw, were used to analyze the materials. In the analyses performed, it was evidenced that the MAPbI3-PbS system is presented in the orthorhombic phases for low temperatures (77K and 10 K) and in the tetragonal phase for room temperature. JxV measurements (current density (J) as a function of the applied voltage (V)) were performed for the electrical characterization of the photovoltaic system. The devices were constructed in an open atmosphere, thus reaching the highest efficiency of 3.4% for pure perovskite, demonstrating lower efficiency values for the hybrid film of MAPbI3-PbS. Analysis of PL as a function of excitation power showed a high-intensity emission and narrow line width - superfluorescence (SF) - evidencing coherent state emission at room temperature for the MAPbI3-PbS system, indicating potential application of this material in polariton lasers.