Síntese e caracterização de nanocristais de perovskita de CsPbI3 em matriz vítrea dopados com Ho3+.

Abstract

Perovskite nanocrystals (NCs) play an important role in materials science due to their extraordinary optoelectronic properties. In this context, the present work aimed to synthesize and characterize CsPbI3 perovskite NCs in glass matrix doped with Holmium ions (Ho3+). After fusion synthesis, the obtained samples were submitted to an adequate thermal treatment in order to promote the growth of NCs. Subsequently, the microstructure of the synthesized material was evaluated by Transmission Electron Microscopy (TEM), Selected Area Electron Diffraction (SAED) and X-Ray Diffraction. Optical properties were analyzed by UV-Vis-NIR Optical Absorption Spectroscopy (OA) and Photoluminescence (PL). As main results, TEM images revealed the formation of CsPbI3 NCs with an average size of 7 nm in samples heat treated at 500 °C for 72 h. X-ray diffraction data and SAED patterns indicated the formation of an orthorhombic crystalline structure for CsPbI3, as well as strong evidence that holmium, as a doping element, remained dispersed in the glass matrix. The analysis and overlapping of the AO and PL spectra showed evidence of energy transfer from the NCs of CsPbI3 to Ho3+ ions, a phenomenon known as the antenna effect. From this study, it is concluded that the optical properties of the samples are modified both by heat treatment and by doping with lanthanide. Synthesis and investigation of new materials such as the one proposed in this work allow exploring unique phenomena that arise at the nanometric scale, which offers opportunities for the development of materials with customizable and adjustable properties.