Dispensing Technology on the Route to an Industrial Metallization Process

This study presents a new developed, inline applicable dispensing platform that is equipped with an advanced version of previously introduced parallel dispensing print heads and works as drop-in-replacement in existing manufacturing lines. At process speeds of up to 700 mm•s-1 and a substantially improved process stability, the impact of the resulting contact geometries on optical and ohmic losses was analysed in detail. A reduced finger width as well as an effective width of just 48% after encapsulation of the finger width leads to nearly 50% reduction of shading losses compared to screen printed samples. A substantially improved finger homogeneity leads to similar grid resistances at 20% less silver consumption.
Consequently, recent cell results on industrial emitters (Rsh = 90 Ω/sq.) showed an efficiency increase of up to +0.4%abs. in comparison to standard single screen printing reaching top values of η = 20.5% on PERC structures. A key improvement of the technology is the new ability to process certain metal pastes originally designed for screen printing applications and thus keep in track with fast emerging paste development. Successfully evaluated screen printing pastes then can be rheologically adapted in order to reach ultrafine contact fingers at high aspect ratios and extract the whole advantage of this non-contacting printing technology.