Síntese dos cristais de perovskitas do tipo Cs1-xRbxPbBr3

Abstract

Inorganic halide perovskites have the chemical formula ABX3 of which A+ = Cs, Rb; B2+ = Sn, P b, and X− = Cl, Br, I. They have attracted great interest due to their easy synthesis and their extraordinary optical and electronic properties with potential technological applications. Since 2009, these materials have been used in the fabrication of solar cells. The first perovskite solar cell being composed of CH3N H3P bBr3/T iO2. In this work, Cs1−xRbxP bBr3 crystals were synthesized using the solution evaporation method at fixed-temperature. The crystals were obtained with different concentrations of rubidium, where x = 0, 00; x = 0, 05; x = 0, 10 and x = 0, 30. X-ray Energy Dispersive Spectroscopy (EDS) allowed the determination of the chemical composition of the samples. The Cs1−xRbxP bBr3 crystals grew rapidly, within a week and a month, with a hopper-like growth pattern. Powder X-ray diffraction measurements, revealed that all crystals exhibit orthorhombic symmetry belonging to the Pnma space group at room temperature. The lattice parameters, determined by the Rietveld method, showed increase in the a and b parameters and decrease in the c parameter with increasing rubidium concentration. The CsP bBr3 crystal has a luminescence peak at 527 nm, while the mixed crystals have peaks at wavelengths between 485 nm and 526 nm at different points of the crystals. Photoluminescence and EDS results indicate that the Cs1−xRbxP bBr3 crystals formed of regions with different rubidium concentrations due to the hopper-like growth pattern.