Ultrafast spectroscopy applied to heavy metal-free semiconductor nanocrystal materials

• Grant number: 20/16077-6
• Support Opportunities: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): September 01, 2021
• Effective date (End): August 31, 2023
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Lázaro Aurélio Padilha Junior
• Grantee: Brener Rodrigo de Carvalho Vale
• Host Institution: Instituto de Física Gleb Wataghin (IFGW). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Semiconductor nanomaterials are an important class of functional materials for many applications such as photovoltaics, light emission diodes, solar concentrators, biomarkers, photocatalysis, etc. However, many of these nanomaterials are based on heavy metals such as Pb and Cd in their chemical composition, which makes difficult for application on a large scale. For this reason, some researches have been proposed eco-friendly materials, heavy metal-free, such as Copper Indium Sulfide (CIS), Indium Phosphide (InP) Quantum Dots (QDs), and Cesium Copper Halides (CCH) nanomaterials. To deeply understand, appointing proper applications, and exploring the maximum efficiency of these materials is essential to know their optoelectronic properties. Fluorescence time-resolved and transient absorption spectroscopies associated with femtosecond lasers are excellent tools to explorer such properties in novel materials such as CIS and InP QDs and CCH. This project aims to couple fluorescence time-resolved spectroscopy to electrochemical technique to unravel the origin of the broad emission spectrum of CIS QDs. The second section is dedicated to the synthesis and characterization of CCH nanomaterials to unveil their linear and non-linear optical properties such as one and two photons absorption cross-section, the biexciton Auger decay, the biexciton binding energy, and amplified spontaneous emission experiments. The third section will be dedicated to study hole and hot electron extraction in InP QDs. However, this last process will be carried out by pump-push-probe technique which provides better resolution for hot electron extraction. (AU)