Study of the Optical Properties of Perovskite Quantum dots

• Grant number: 24/14341-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2024
• End date: December 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: João Batista Souza Junior
• Grantee: Laís Fernanda Medeiros Ruela
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Campinas , SP, Brazil

Abstract

The economic, social, and technological impact of semiconductors is unmeasurable since humanity depends on semiconductor-based optoelectronic devices such as TVs, cell phones, solar cells and countless others. The synthesis and optimization of Perovskites nanoparticles called quantum dots have been attracting attention due to their high fluorescence quantum yield with high color purity emissions (narrow emission bands), being excellent candidates for high-efficiency optoelectronic devices. Perovskites have low chemical stability and present degradation in the presence of moisture. Thus, different structures such as Perovskites CsPbBr3, Cs3Bi2Br9 and Cs3Sb2X9 (X = Cl-, Br- and I-) will be synthesized to evaluate their chemical and structural stability and compare with their optical properties. Obtaining Perovskites with optimized optical properties requires the control of their chemical and structural since structural defects in both the bulk and the surface lead to non-radiative emissions and, consequently, a decrease in quantum yield and an increase in photoluminescence lifetime. Advanced techniques in Transmission Electron Microscopy (TEM) and XRD will be used to study the nanomaterials with the collaboration of LNNano specialists, the student will supervise the structure characterization and work on data processing. Thus, this project aims to evaluate and optimize the structural characteristics of quantum dots by studying their optical properties linked to their structural characteristics. In this way, it is expected to understand the influence of lead exchange in Perovskites, seeking to maintain the optical properties reported in the literature.