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Abstract(s)
Esta dissertação teve como objetivo o desenvolvimento de células solares sensibilizadas por
corantes (DSSCs) transparentes com uma maior eficiência, incorporando novos materiais e
aplicando técnicas alternativas de deposição.
A produção das DSSCs envolveu diversas etapas como a preparação das formulações
constituintes do fotoânodo e sua posterior deposição, preparação dos cátodos e montagem das
células.
Prepararam-se formulações de apenas óxido semicondutor, de óxido semicondutor e
nanopartículas de ouro sintetizadas pelo método “in situ” e de óxido semicondutor e
nanopartículas de ouro sintetizadas pelo método de Martin com quantidades de AuNPs
diferentes, sendo estas 23,9% e 47,6% (m/m). Todas as formulações foram depositadas no
fotoânodo recorrendo à técnica de doctor blade. De forma a evitar a recombinação eletrónica e
consequentemente aumentar a sua eficiência, aplicou-se um tratamento superficial nos
fotoânodos de apenas óxido semicondutor e nos de óxido semicondutor com 47,6% de
nanopartículas de ouro. No que diz respeito aos cátodos, estes foram preparados através da
deposição de uma solução de ácido cloroplatínico hexahidratado por spin coating, e aplicação
de um tratamento térmico com a finalidade de formar nanopartículas de platina. De forma a
atingir o principal objetivo da dissertação, células solares transparentes, realizou-se a deposição
do óxido semicondutor recorrendo à técnica de sputtering que permitiu obter um fotoânodo
mais transparente.
Os parâmetros de desempenho fotovoltaico das células solares foram analisados recorrendo a
um simulador solar por voltametria de varrimento linear. Posteriormente, realizou-se o
tratamento estatístico dos resultados obtidos recorrendo à análise ANOVA. Através dos
resultados obtidos foi possível concluir que a incorporação de nanopartículas de ouro não teve
o impacto esperado, não aumentando a eficiência da célula solar. Por outro lado, o tratamento
superficial contribuiu para o aumento da eficiência. Quando utilizada a técnica de sputtering as
eficiências obtidas foram menores comparativamente às obtidas pela técnica de doctor blade.
This dissertation aims to develop transparent dye-sensitized solar cells (DSSCs) with higher efficiency by incorporating new materials and applying alternative deposition techniques. The fabrication of DSSCs involved several steps, such as the preparation of photoanode component formulations, followed by the preparation of photoanodes, the preparation of cathodes, and the assembly of cells. Formulations of only semiconductive oxide, semiconductive oxide with gold nanoparticles synthesized by the "in situ" method, and two formulations of semiconductive oxide with gold nanoparticles synthesized by the Martin method with different amounts of AuNPs (specifically 23.9 wt% and 47.6 wt%), were prepared. These formulations were deposited on the photoanode using the doctor blade technique. Subsequently, a surface treatment was applied to some photoanodes with only semiconductive oxide and the photoanodes of semiconductor oxide with 47.6 wt% gold nanoparticles to avoid electronic recombination inside the solar cell. The cathodes were prepared by depositing a solution containing chloroplatinic acid hexahydrate via spin coating. To achieve the main goal of the dissertation, the development of a transparent solar cell, the deposition of the semiconductor oxide was carried out using the sputtering technique. This deposition technique allowed us to obtain a more transparent photoanode. The photovoltaic performance parameters of the solar cells were analyzed using a solar simulator through linear sweep voltammetry. Afterward, statistical treatment of the obtained results was conducted using ANOVA analysis. The results showed that the incorporation of gold did not have the expected effect and did not increase the efficiency of the solar cell. On the other hand, the surface treatment contributed to an increase in efficiency. When the sputtering technique was used, the efficiencies achieved were lower than those achieved with the doctor blade technique.
This dissertation aims to develop transparent dye-sensitized solar cells (DSSCs) with higher efficiency by incorporating new materials and applying alternative deposition techniques. The fabrication of DSSCs involved several steps, such as the preparation of photoanode component formulations, followed by the preparation of photoanodes, the preparation of cathodes, and the assembly of cells. Formulations of only semiconductive oxide, semiconductive oxide with gold nanoparticles synthesized by the "in situ" method, and two formulations of semiconductive oxide with gold nanoparticles synthesized by the Martin method with different amounts of AuNPs (specifically 23.9 wt% and 47.6 wt%), were prepared. These formulations were deposited on the photoanode using the doctor blade technique. Subsequently, a surface treatment was applied to some photoanodes with only semiconductive oxide and the photoanodes of semiconductor oxide with 47.6 wt% gold nanoparticles to avoid electronic recombination inside the solar cell. The cathodes were prepared by depositing a solution containing chloroplatinic acid hexahydrate via spin coating. To achieve the main goal of the dissertation, the development of a transparent solar cell, the deposition of the semiconductor oxide was carried out using the sputtering technique. This deposition technique allowed us to obtain a more transparent photoanode. The photovoltaic performance parameters of the solar cells were analyzed using a solar simulator through linear sweep voltammetry. Afterward, statistical treatment of the obtained results was conducted using ANOVA analysis. The results showed that the incorporation of gold did not have the expected effect and did not increase the efficiency of the solar cell. On the other hand, the surface treatment contributed to an increase in efficiency. When the sputtering technique was used, the efficiencies achieved were lower than those achieved with the doctor blade technique.
Description
Keywords
DSSCs Photoanode Semiconductor oxide Gold nanoparticles Doctor blade Sputtering DSSCs Fotoânodo Óxido semicondutor Nanopartículas de ouro