During the last few years, solar energy conversion by photovoltaics and solar receivers has grown enormously. For the future, efficient and durable products at low cost are necessary and laser technology offers many opportunities to realize this. Two of these technologies are discussed in this paper.
First, a technology is discussed for producing solar receivers. A requirement for a solar receiver is a vacuum between the absorber and the cover glass tube during the operation lifetime of at least 25 years. To realize this requirement, glass and metal must be directly fused. A CO2-laser in combination with a process temperature controller is used instead of a gas flame to obtain a stable process and to avoid chemical interaction between flame and fusing zone. This paper shows the results of the developed laser process compared to a flame fusing process.
The second technology discussed is used for producing silicon wafer based solar cells. A method to reduce costs is reducing the wafer thickness. Consequently, contact and pressure-free laser processing has large advantages. Experimental investigations are discussed for drilling holes for new solar cell concepts. Damage to the silicon around the processing area should be avoided. Results obtained with different laser types are compared regarding the quality, speed and costs.