German research cluster reduce the cost for PECVD PERC solar cell passivation

The efficiency of solar cells can be increased by the PERC technology (Passivated Emitter Rear Cell). The current yield increases because the back of the solar cell is passivated. However, additional process steps are needed for the production process adding to the over all production cost.

 

Circular Inductively Coupled Plasma (ICP) Calculated electron energy distribution for circular ICP plasma Induced electric field strength calculated from ICP coil current (Picture from SIMPLEX) 

 

Most commonly used passivation layers are aluminum oxide (Al2O3) or silicon nitride (SiNx) and until now Atomic Layer Deposition (ALD) has been able to produce th highest layer quality enable the use of thinner layer thickness and hence also save material cost (TMA precursor).

The German Federal research project Simplex has succeeded in significantly improving the production process of highly efficient PERC solar cells on the basis of plasma-assisted chemical vapor deposition (PECVD), while at the same time potentiall reducing the costs.

"For the industrial plasma coating process, the thickness of the most important layer for the PERC cell could be successfully reduced to a quarter without lowering cell efficiency," said Coordinator Dr. Bernhard Cord of the company Singulus Technologies AG

For example, PERC solar cells with 4 nanometer (nm) thick aluminum oxide layers could be produced instead of the current 20 to 30 nm and an efficiency of 21.0 percent.

More information belwo (in German):

German funding project Simplex : LINK
News article (SolarServer) : LINK 

Cluster partners

SINGULUS TECHNOLOGIES AG, Kahl am Main (coordinator)
Fraunhofer-Institut für Solare Energiesysteme (ISE), Freiburg
Fraunhofer-Institut für Schicht- und Oberflächentechnik (IST), Braunschweig
Plasmetrex GmbH, Berlin
Plasus GmbH, Kissing
SENTECH Instruments GmbH, Berlin
TRUMPF Hüttinger GmbH + Co. KG, Freiburg