• ITO
• photodoping
• electrochemical
• nanoparticles
• plasmonics
• magneto-optics
• spectroelectrochemistry

This thesis work is focused on the design and preparation of heavily doped semiconductors, in particular Indium Tin Oxide (ITO), in the form of colloidal nanoparticles that exhibit strong optical and magneto-optical response in the near infrared spectral range. The nanoparticles were prepared by thermal decomposition of organometallic precursors and characterized morphologically and structurally by transmission electron microscopy (TEM) and powder X-ray diffraction (PXRD).
Due to aliovalent doping, the nanoparticles exhibit plasmonic properties in the near infrared spectral range. The possibility of introducing further electrons into these nanoparticles, thus changing the optical response through UV irradiation, or applying an electrochemical potential is here investigated. The experimental setup for photo-doping and electrochemical doping with in-situ monitoring of the optical and magneto-optical properties during the doping process were optimized in this work.
The near infrared optical and magneto-optical properties of the nanoparticles were analysed by extinction and magnetic circular dichroism spectroscopy before and during the photodoping process. Critical free electron parameters were extracted from the analysis of the optical and magneto-optical spectra. Magnetic Circular Dichroism was demonstrated to be a valuable tool to evaluate free electron parameters and their variation during the photodoping and electrochemical doping.