In light of the meteoric growth in production capacity and ever more efficient cell concepts and processes, quality assurance is becoming increasingly significant in solar cell manufacture and, internationally, is becoming a determining competitive factor. Because of the high level of automation and rising throughput of manufacturing lines, efficient quality control requires rapid inline metrology and powerful systems for data acquisition and statistical data analysis.
At Fraunhofer ISE, in our Photovoltaic Technology Evaluation Centre (PV-TEC), we test many different inline measurement methods with regard to their suitability for use in quality and process control under industrial conditions. Using available methods, we are in a position to measure all significant quality parameters on starting wafers, solar cell precursors and finished solar cells, and assign them at wafer level to a wafer tracking system. On the one hand, this enables efficient control of the individual processes and, on the other hand, the provision of comprehensive QC data records on the experiments performed. A direct link between the characterization laboratory and the manufacturing line additionally permits the measurement of random samples for detailed analyses in parallel to the process using many different offline measurement methods.
In addition to quality assurance for research operations in PV-TEC, our research can be divided into three fields: