Influence of firing ambience on fire-through silver contact metallization for crystalline silicon solar cells

Screen-printed Ag thick-film metallization is used in the photovoltaic industry for the front-side emitter contacts of crystalline silicon solar cells owing to its cost-effectiveness and high throughput. In order to obtain a better understanding for the formation of Ag crystallites at the paste/Si interface and the correlation between the electrical properties and microstructure of the contact, the firing treatment was carried out under various oxygen partial pressures (Po₂) and the contact resistance was determined by a transfer length method (TLM) measurement. The present study results demonstrate strong dependences of the Ag crystallite formation and the contact resistance on Po₂ in the firing ambience.