Environmental Tests of Metallization Systems for Terrestrial Photovoltaic Cells.

摘要

Seven different solar cell metallization systems were subjected to temperature cycling tests and humidity tests. Temperature cycling excursions were -50 deg C to 150 deg C per cycle. Humidity conditions were 70 deg C at 98% relative humidity. The seven metallization systems were: (1) Ti/Ag, (2) Ti/Pd/Ag, (3) Ti/Pd/Cu, (4) Ni/Cu, (5) Pd/Ni/Solder, (6) Cr/Pd/Ag, and (7) Thick Film Ag. All of the seven metallization systems showed slight to moderate decreases in cell efficiencies after subjection to 1000 temperature cycles. Six of the seven metallization systems also evidenced slight increases in cell efficiencies after moderate numbers of cycles, generally less than 100 cycles. The copper-based systems showed the largest decrease in cell efficiencies after temperature cycling. All of the seven metallization systems showed moderate to large decreases in cell efficiencies after 123 days of humidity exposure. The copper-based systems again showed the largest decrease in cell efficiencies after humidity exposure. Graphs of the environmental exposures versus cell efficiencies are presented for each of the metallization systems, as well as environmental exposures versus fill factors or series resistance. (ERA citation 12:015603)