technology report 04

ENERGY & ENVIRONMENT
Silver for
making better
use of sunlight
Metallization pastes containing silver make solar
cells highly efficient – With development centers
in Asia, Europe and the USA, Heraeus has its
finger on the pulse of the photovoltaic industry
Converting sunlight into power is still a future market with high growth potential.
According to a study by the DG Joint Research Center of the European Commission,
enormous progress has been made in the adoption of photovoltaic technology,
especially in Europe, where the installed capacity is estimated to average around 14
gigawatts per year. By 2020, it is estimated that the installed photovoltaic capacity
will reach 100 gigawatts in Europe alone. And according to a study by the European
Photovoltaic Industry Association (EPIA), this milestone was already passed worldwide
in 2012. The aim is to produce as much electricity as possible from sunlight.
In this context, silver metallization pastes manufactured by Heraeus contribute to
improving the efficiency of silicon solar cells. The requirements for future generations
of paste are high efficiency combined with low consumption and silver content. The
silver pastes are conventionally applied to the solar cell by means of a screen-printing
process, and dried. The cells are then sintered in a high-temperature process in order
to produce a conductive connection to the emitter. Following this production step,
the finished cells are tested, and after passing the test are processed into modules.
The silver pastes are used to produce very fine, highly conductive contact lines on
the indigo-colored solar cells. These supply the electrical contacts for the wafer.
High-performance metallization pastes ensure that the solar energy obtained is
optimally utilized. Heraeus develops and distributes pastes for conventional solar
cells (for front and rear metallization) and for novel cell designs (such as n-type,
PERC and MWT cells), as well as pastes for low-temperature applications.
technology report Issue 4 | 2013
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