Heraeus Photovoltaics Business Unit presents new pastes
The Heraeus Photovoltaics Business Unit are featuring two new front-side metallization pastes for c-Si solar cells during the Intersolar North America 2014 at the Moscone Center in San Francisco. The SOL9620 Series and SOL9621 Series represent Heraeus' latest pastes that enable cell manufacturers to further increase their c-Si cells' conversion efficiencies to an industry-leading level and beyond. The development of these two products are for customers with slightly different LDE applications and processing; however both pastes provide superior cell efficiencies while lowering customers' cost per watt.
The SOL9620 Series is outstanding for ultra-lightly doped emitters [ULDE], with surface doping concentrations down to 1xE20/cm3. The SOL9620 Series has demonstrated the highest performance during customer testing, particularly on monocrystalline wafers. Relative to the SOL9610 Series on 110 Ω/sq. monocrystalline wafers, the SOL9620 Series demonstrated an 80% reduction in contact resistance; approximately a 3mV increase in Voc; and up to 0.25% absolute efficiency gains. The unique chemistry of SOL9620 Series also enable the ability to be fired through different combination of passivation layers and at a relative lower peak temperature than standard firing temperatures. This is ideal for PERC applications.
The SOL9621 Series has demonstrated great results for regular emitter and LDE applications. When tested against Heraeus' SOL9610 Series on 85 Ω/sq. multicrystalline wafers, customers experienced higher electrical performance: a 50% reduction in contact resistance; a 1 "“ 2 mV increase in Voc; and greater than 0.10% absolute efficiency gains. The SOL9621 Series provides customers with a flexible and robust process window, which aids in providing a lower manufacturing cost. SOL9621 is also highly recommended for the 1st and 2nd layer of double printing applications with customers confirmed efficiency gain greater than 0.10% over the best commercially available double printing pastes.
