Wide-Band Gap Perovskite Nanostructures: Synthesis, Advanced Structural Characterization and Optoeletronics Properties

• Grant number: 23/00984-2
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date until: December 01, 2023
• End date until: August 31, 2027
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: João Batista Souza Junior
• Grantee: Olavo Fiamencini Verruma
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovação (Brasil). Campinas , SP, Brazil

Abstract

Semiconductor materials have high economic, technological, and social importance, since currently society uses daily electronic devices that depend on these materials such as TV, cell phones, computers, and countless other electronic components. Specifically for the material to be studied in this project, that is, perovskites on a nanometer scale, also known as perovskite quantum dots, the production of devices with high quantum fluorescence yield and controlled optical properties is essential for optimizing the use of semiconductors in optoelectronic devices. Repeatedly, to obtain perovskites with adjusted optical properties, especially with emissions in blue, it is necessary to have precise morphological, chemical, and structural control of the nanoparticles and, consequently, statistically accurate and representative structural characterization techniques capable of evaluating the defects at the atomic level of the systems produced. Advanced techniques in Transmission Electron Microscopy (TEM) can provide crucial information both morphological (requiring statistical data from high-resolution images) and structural correlations for nanomaterials. However, some components of the perovskites interact with the electron beam through inelastic scattering inducing the decomposition of the structures. In the literature, few advanced studies in TEM on perosvkists are reported, precisely because of the difficulty of circumventing the damage caused by the electron beam. Thus, in this project new methods of sample preparation and data collection will be explored as data collection from low dose and serial images (a series of images will be added and aligned to generate a final image, a process similar to Cryo-EM. Thus, we intend to provide important information for the determination of structural defects that are harmful to the efficiency of devices and that can be improved through new methods of synthesis and ligand exchanges. To achieve this goal, it is intended to characterize in an advanced way the perovskite-type nanostructured systems in order to generate samples with fewer defects and greater photoluminescence emission for future applications in perovskite light-emitting diodes (PeLEDs).