CÉLULAS SOLARES FINAS EM SILÍCIO TIPO N: AVALIAÇÃO DE DIFERENTES PASTAS METÁLICAS PARA CONTATO ELÉTRICO DA FACE DOPADA COM BORO

Abstract

The main goal of the solar cell industry is to reduce the production cost so that the photovoltaic technology can be competitive with other kinds of electricity generation. The combination of the use of n-type silicon to obtain higher efficiency devices and thinner wafers can be an alternative for reducing cost. The aim of this work is to present the analysis of different metal pastes to form the electrical contact grid of the boron doped face in solar cells fabricated in thin wafers of n-type Czochralski-growth solar grade silicon. The p+nn+ and n+np+ structures were studied. By comparing metal pastes of Ag, Ag/Al and Al, we concluded that the latter enabled the manufacture of the more efficient solar cells. The aluminum metal paste has to be screen-printed before the deposition of the dielectric film of TiO2 because it does not etch-through the thin film during firing of metal pastes. By using aluminum paste deposited on the boron doped face, the solar cells with n+np+ and p+nn+ structures reached efficiencies of 13.4% and 12.6%, respectively, values relatively low due to the use of thin solar grade silicon wafers and the absence of surface passivation. (English) [ABSTRACT FROM AUTHOR]