Self-Assembly of Semiconductor Nanoparticles for Optical Applications

Great developments in the synthesis routes of producing high quality nanoparticles with tunable physical and chemical properties makes them ideal building blocks for the next generation of nanoscale electronic devices. Researchers have shown that deposition of colloidal nanoparticles on a surface form variety of patterns, which is mainly driven by the diffusion limited self-assembly process. Through this proposal, we aim to investigate the possibility of controlling the self-assembly pattern formation of SnO2-dye complex. The role of dye molecules is either to harvest light and transfer the charge to SnO2 self-assembly pattern or to make the pattern fluorescent. These two situations can be achieved through a proper selection of dye molecules based on the relative position of HOMO-LUMO energy levels with respect to the conduction and valance band positions of SnO2 nanoparticles. Various optical spectroscopy and microscopy measurements like UV-Vis absorption, emission, fluorescence lifetime, widefield imaging etc. will be performed with a focus to investigate the optical and photo-induced charge transfer process in dye-nanoparticle self-assembly patterns. Further, AFM measurements will be carried out to investigate the morphology and electrostatic properties of the patterns.

Great developments in the synthesis routes of producing high quality nanoparticles with tunable physical and chemical properties makes them ideal building blocks for the next generation of nanoscale electronic devices. Researchers have shown that deposition of colloidal nanoparticles on a surface form variety of patterns, which is mainly driven by the diffusion limited self-assembly process. Through this proposal, we aim to investigate the possibility of controlling the self-assembly pattern formation of SnO2-dye complex. The role of dye molecules is either to harvest light and transfer the charge to SnO2 self-assembly pattern or to make the pattern fluorescent. These two situations can be achieved through a proper selection of dye molecules based on the relative position of HOMO-LUMO energy levels with respect to the conduction and valance band positions of SnO2 nanoparticles. Various optical spectroscopy and microscopy measurements like UV-Vis absorption, emission, fluorescence lifetime, widefield imaging etc. will be performed with a focus to investigate the optical and photo-induced charge transfer process in dye-nanoparticle self-assembly patterns. Further, AFM measurements will be carried out to investigate the morphology and electrostatic properties of the patterns.