Investigating metal-semiconductor contacts in solar cells using magnetic field measurements

While solar cells and modules are already a mature technology in mass production, contacting schemes are constantly evolving. For example, multi busbar/multi wire contacting systems are currently being developed. During the development and the production of such technologies, it is critical to optimize and to systematically monitor their performance.In this paper, we find that different contacting fault types can be identified by inducing specific current flow patterns through the contacts of a single side of a solar cell and measuring the resultant 2D magnetic field image. Additionally, we explore the use of circuit network modelling in conjunction with these magnetic field images to gain further insights about the contacting schemes. Excellent agreement between circuit simulations and magnetic field measurements was achieved by combining different current flow patterns as demonstrated on a multi-wire contacted solar cell.