The work package starts with the theoretical analysis of solar cell results. Here, measurements of quantum efficiency, reflection, partial cell voltage, fill factor and resistance are compared with theoretical calculations to predict how changes in the layer structure and processing will affect the multi-junction solar cell. Modelling at Fraunhofer ISE is now able to make very precise predictions. In addition, it provides information about the desired layer thickness and composition of each individual semiconductor layer in order to achieve current matching. The modelling provides information about the concentration at which the highest efficiencies can be achieved and thus supports the development of an optimized mask set.
In addition to modelling, this work package will grow optimized solar cell structures on GaAs and InP and fine-tune cell structure and process technology to achieve the ambitious goal of a multi-junction solar cell with 50% efficiency.