Dielectric spectroscopy of colloidal quantum dots in apolar liquids

Abstract

This thesis deals with the measurement of the permanent electric dipole moment and net charge of colloidal quantum dots (QDs) in apolar liquids. Their electric properties are essential for understanding their optical properties, colloidal interactions, and electric field directed assembly. In view of the optical sensitivity of QDs, a non-optical measurement technique was chosen: dielectric spectroscopy. In conclusion, dielectric spectroscopy has revealed the influence of structure formation on the dipolar relaxation of colloidal quantum dots in apolar liquids. Measurements of both the electric double layer dynamics in dielectric spectroscopy measurements and the electrophoretic and electroacoustic motion of charged colloidal particles at low ionic strength point to insufficient development of the theoretical basis of the techniques. As a result, their physical interpretation remains a challenge.