Fraunhofer ISE Team Receives Innovation Award Laser Technology 2014

A research team at Fraunhofer ISE was awarded the Innovation Award Laser Technology 2014 for its Laser Fired Contact (LFC) technology used for the production of highly efficient silicon solar cells. Dr. Ralf Preu, division director of Production Technology and Quality Assurance, Dr. Jan Nekarda and Martin Graf, all scientists at Fraunhofer ISE, accepted the award on May 7, 2014 at the festive Coronation Hall of Aachen’s city hall in Aachen, Germany.

The European science award is bestowed every two years by the associations Arbeitskreis Lasertechnik e.V. (AKL) and the European Laser Institute (ELI). An international jury comprised of nine experts chose three finalists out of a total of 23 applicants.

“We are delighted to have received this honor that is not only a recognition of our work but also the innovative strength of photovoltaic research and industry throughout Europe,” said Dr. Preu.

The prize-winning LFC technology is a cost-efficient procedure for rear-side contacting and allows current collection to take place on the rear side of silicon solar cells. In less than a second, a pulsed laser drills several ten thousand contacts in an aluminum layer on the rear side of a solar cell. LFC combines high efficiency potential with low manufacturing costs, since it replaces the expensive and slower structurization steps previously necessary for the rear side passivation of solar cells.

Fraunhofer ISE’s work on LFC technology began more than 10 years ago under the direction of Dr. Preu and has led to patented procedures.

“With the LFC technology of the first generation, we proved that highly efficient solar cells could be manufactured with fast laser processing. With the second generation we moved the manufacturing procedure up to the industrial processing level,” explained Dr. Preu. “Now we are working on the third generation of this technology, in which we expect to take a large innovative step forward towards the cost-effective production of highly efficient solar cells.”

The researchers first applied the LFC technology to aluminum films grown by vapor deposition on the rear side of solar cells. Ten years ago the Fraunhofer researchers used this process to achieve a world record efficiency for multi- crystalline silicon solar cells, which is still valid today. The necessary adoption of the process for screenprinted aluminum – the widespread industrially available metallization technology – was successfully carried out.

About four years ago, the technology transfer to the industry partner Q-Cells began. Q-Cells continued to optimize the technology and achieved cell and module record efficiencies of 19.5% for large-area multi-crystalline solar cells and 18.5% for standard-sized modules.