Síntese e caracterização de pontos quânticos coloidais de seleneto de cádmio e sua modificação superficial para aplicações em dispositivos fotovoltaicos

Abstract

This work presents the synthesis of colloidal quantum dots (QDs), nanocrystalline particles that have a diameter between 2 and 20 nm. Material extensively studied due to its special optical-electronic properties and its potential technological application, as in photovoltaic devices. Through the organometallic route different sizes of cadmium selenide (CdSe) QDs were obtained, in which they were characterized by optical absorption spectroscopy in UV-Vis and photoluminescence. A software was developed to calculate the mean size of the nanocrystals and their concentration in solution. By means of ligand exchange reaction, the surface modification of the QDs with the bifunctional ligand 3-Mercaptopropionic Acid (MPA) was performed, for better applicability in photovoltaic devices. The evidence of the binding of the ligand on the surface of the QDs was inferred by the spectroscopic techniques of absorption molecular in UV-Vis and photoluminescence and confirmed by infrared molecular vibrational spectroscopy. Finally, an analysis of the materials obtained in this work was made for the potential application in photovoltaic devices.