Low-Temperature Ag-Paste Screening for Silicon Heterojunction Solar Cells and Modules

This paper addresses the testing of eleven different low-temperature pastes (LTP) for silicon heterojunction (SHJ) solar cells. In the LTP screening different pastes from different suppliers were printed on the front side of industrial rear-emitter transparent conductive oxide TCO precursors with industry relevant screens. The pastes are compared with regard to (1) electrical properties of the grid fingers for screen openings ranging from 50 μm over 40 μm down to 30 μm and (2) the suitability for module integration which is addressed by peel tests after the soldering step and (3) performance on cell level for busbarless (0BB) and five busbar (5BB) technology as well as (4) economic factors like laydown and fast printing compatibility which affects through-put of screen printing in the production line.