| Nanocrystal (NC) thin films are of significant interest for a variety of optoelectronic device applications such as photodetectors, light emitting diodes (LEDs) and solar cells due to the dominance of quantum size effects in the electronic structure. There is intensive research focusing on improving the conductivity and carrier mobility in semiconductor NC films by reducing the inter-NC spacing. This can be done by removing the bulky organic surfactants by thermal annealing or exchanging them with smaller ligands, either in solution phase before depositing the NCs as thin films or in the solid phase after deposition. Brock and co-workers have employed sol-gel methods to assemble metal chalcogenide NCs into gels, xerogels and aerogels. In these materials NCs are connected through covalent bonding of anionic species (diselenide or polyselenide in the case of CdSe NCs) which are formed on the surface during the gelation process. The present study focuses on extending sol-gel method to fabricate thin films of CdSe and evaluating the efficiency of ligand removal and assembly process by performing gravimetric, microscopic, spectroscopic studies and photoconductivity measurements. Additionally, the application of porous chalcogenide aerogels in hybrid photovoltaic devices will be presented. |
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