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• PID tests for crystalline Si photovoltaic modules without front cover glass and using cells with various electrode pastes of controlled additive contents were performed. • This phenomenon is similar to that induced by Na in the front cover glass, but, it requires the shorter time duration as compared with the case of Na in the front cover glass. • In addition, it is found that Li in the paste also causes the PID equivalent to that by Na in the paste. Sodium (Na) and lithium (Li) in the silver (Ag) paste cause the potential-induced degradation (PID), while the PID of p-type crystalline silicon (Si) photovoltaic modules is caused by Na in the front cover glass. Some Ag pastes contain these elements to control the firing properties in solar cells fabrication. In order to eliminate the effect of Na and other elements in the front cover glass on PID, PID tests for crystalline Si photovoltaic modules without front cover glass and using cells with various electrode pastes of controlled additive contents were performed. When the Ag paste with Na is used, the shunt resistance decreases and the PID occurs. This phenomenon is similar to that induced by Na in the front cover glass, but, it requires the shorter time duration as compared with the case of Na in the front cover glass. In addition, it is found that Li in the paste also causes the PID equivalent to that by Na in the paste. [ABSTRACT FROM AUTHOR]

In the field of silicon heterojunction (SHJ) solar cells, great successes on improving production processes have been achieved in the last years, however further improvements in the case of metallization are required to obtain higher market share. Therefore, lower Ag laydowns and higher process throughput are demanded. This study presents the impact of filament stretching on Ag-electrode shapes and laydown during temperature-controlled micro-extrusion, known as parallel dispensing. Dispensed metal grids ensure higher cell performances than screen-printed grids. It has been discovered that the maximum use of filament stretching benefits the solar cell efficiency due to narrower Ag-electrodes and less silver consumption. We have shown a low Ag laydown per 157.35 mm line of m Ag = 0.27 mg electrode-1 in average. An efficiency gain of Δη A = + 0.26% abs. has been demonstrated by the maximum usage of filament stretching. Further, a novel parameter that values the effectiveness of silver usage and enables the comparison between different printing processes has been introduced. We have demonstrated that silver is used more effectively by up to +74% rel. when the low-temperature curing paste is dispensed compared to screen printing because dispensed electrodes show an almost perfectly homogeneous shape. • Temperature-controlled filament stretching phenomenon during micro-extrusion obtains higher solar cell performances and higher throughput-rates. • Filament stretching phenomenon is process-specific and paste-specific. • Novel parameter is introduced to value the effectiveness of silver usage in printed structures. • Silver is used more effectively in dispensed lines than in screen-printed lines. [ABSTRACT FROM AUTHOR]