Fundamental parameter measurements of high efficiency single crystal silicon concentrator cells

In order to optimize production processes used to make solar cells, it is helpful to have experimental access to the effects of the process by measuring parameters more fundamental than those derived from the current-voltage characteristics of finished devices. The authors have developed a set of nine small cells which can be made on a single substrate using the same process as is used for standard cells. Variable metal coverage on this set allows the extraction of fundamental parameters, such as surface recombination velocities, from measurements of sample reflectance, quantum efficiency, and current-voltage characteristics. The method provides an excellent means for feeding back information to engineers working to design and optimize both high-efficiency and large-scale production processes.