Prototype of the solar cells (IMAGE) Forschungszentrum Juelich Caption Prototype of the solar cells in laboratory size (TPC - Transparent Passivating Contact). Four solar cells, each measuring four square centimeters, can be seen on the silicon wafer, each of which is contacted and framed with screen-printed silver contacts. Credit Forschungszentrum Jülich Usage Restrictions Please give credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.