Characterization and Cell Performance of Al Paste with an Inorganic Binder of Bi2O3-B2O3-ZnO System in Si Solar Cells

Abstract

In this study, eco-friendly Pb-free Bi2O3-B2O3-ZnO glass frits were selected as an inorganic additive for the Al paste used in Si solar cells. The effect of glass chemistry on the electrical property of the Al electrode and on the cell performance was investigated. The results showed that as the molar ratio of ZnO to B2O3 increased, the glass transition temperature and softening temperature decreased because of the reduced glass viscosity. In Al screen-printed Si solar cells, as the molar ratio of ZnO to B2O3 increased, the sheet electrical resistance of the Al electrode decreased and the cell efficiency increased. The microstructure of the sintered electrodes showed that the uniformity and thickness of the back-surface field were significantly influenced by the glass chemistry.