Abstract
We report an approach for nanostructured photovoltaic devices using functionalized semiconductor nanocrystal quantum dots (NQDs) by incorporation of the functional ligand t-butoxycarbonyl (t-BOC) which has an acid-labile moiety. This change in the surface chemistry results in the ability to photo-pattern the NQDs, where desired, for a number of optoelectronic device geometries with sub-micron patterning capability. This also enables the fabrication of multi-layered nanostructure photovoltaic devices. We demonstrate an improved photoconducting device, using the patterning and ligand modification process, as well as a bi-layered solar cell using CdTe and CdSe NQDs. The photoconductor has the metal semiconductor metal structure and it shows at least 3 times higher conductivity and photo-response at an electric field of 300kV/cm when using the t-BOC modified QDs. Moreover, the functionalized NQDs enable all solution processed multilayered and patterned structures without high temperature sintering or additional chemical treatment. By using this method, a bi-layered solar cell was fabricated. The preliminary result shows 0.05% solar conversion efficiency and an open circuit voltage of 0.72V under AM1.5G 1 sun illumination.