Electroplating is a known low-cost metallization technique, but without the use of photolithography, line widths have been limited to structures larger than 10 micrometers. For his master thesis, Callum Gannon developed a maskless laser lithography process which demonstrated how previous limitations could be surpassed achieving line widths of less than 10 micrometers on solar cell substrates.

“This new metallization approach promises lower manufacturing costs and scalability advantages compared with conventional processes,” explained Gannon. The proposed technique was shown to be compatible with low-cost resists and aligns with sustainability goals: resource consumption could be significantly reduced by replacing resource intensive conventional spin-coating and evaporation processes with alternative additive manufacturing processes.

“This work contributes to the development of competitive, industrially scalable, and cost-effective III-V solar cell technology,” said Prof. Dr. Stefan Glunz, Director Division Photovoltaics at Fraunhofer ISE, professor at the University of Freiburg und Gannon’s thesis supervisor. “So far, III-V solar cells are mostly used in space applications. They are highly efficient but more expensive than ‘classic’ silicon solar cells. Making them cost-competitive is the most important prerequisite for a deployment in terrestrial PV power plants”.