Construção de células solares sensibilizadas por corante a partir de nanoestruturas de ZnO obtidas por método hidrotermal / Construction of dye-sensitized solar cells from Nanostructures ZnO obtained by Method Hidroterma

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

01/08/2011

RESUMO

The Photovoltaic (PV) sector has been facing an accelerated development rate within the last decade, which is comparable to the other renewable energy sources, according to the data released by the International Energy Agency (IEA). Therefore, a myriad of R&D activities and technological innovations are under way in order to cut down the manufacturing cost of PV cells. R&D actitivies are focused on enhancing the efficiency of the PV cells by improving the production processes for the industry and towards market deployment. The aim of this work was the growth of oriented ZnO nanostructures for application as photoelectrodes in Dye-sensitized Solar Cells (DSCs). In order to control the morphological properties of the ZnO nanostructures and the growth of oriented ZnO nanostructures, ZnO seed layers were deposited onto pre-oxidized silicon wafers and also onto fluorine-doped tin oxide glass substrate (FTO - SnO2:F) by spin-coating from the resin prepared by the polymeric precursor method. Oriented ZnO nanostructures were then grown over the seed layer through the hydrothermal method. Morphological, structural, and optical properties of the seed layers and ZnO porous films were characterized by Field Emission Gun Scanning Electron Microscopy (FEG-SEM), X-ray Diffraction (XRD) and UV-Vis Absorption Spectroscopy, respectively.Some parameters of the seed layers influenced the morphological properties of the ZnO nanostructures grown by the hydrothermal method. Some ZnO samples endowed with promising morphological properties to enhance charge transport and slow down charge recombination processes were applied as photoelectrodes in DSCs. Current-voltage (I-V) curves of the DSCs were measured under illumination of 100 mW cm-2 and also in the dark. The porous ZnO films endowed with the better mechanical properties and higher dye-loading enabled the assembly of DSCs with higher performance amongst the samples. The highest global energy conversion efficiency achieved in this work was 0.83% under illumination of 100 mW cm-2. DSCs with higher energy conversion efficiencies might be assembled by increasing both the transmittance and thickness of ZnO porous films, besides decreasing the series resistance of the devices in order to provide higher fill factor values.

ASSUNTO(S)

camadas de nucleação i dsc zno seed layer outros cssc zno

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