Fraunhofer ISE unveils contactless testing for IBC solar cells

Fraunhofer ISE, a Germany-based solar research institute, has developed a contactless method to evaluate back-contact solar cell performance. The method uses photoluminescence, contactless electroluminescence, and spectral reflection data under varied excitation conditions. According to Fraunhofer ISE, it measures open-circuit voltage, short-circuit current density, fill factor, and efficiency without physical contact. This approach reduces mechanical stress, cuts maintenance, and increases production throughput to over 10,000 wafers per hour. It is especially suitable for IBC cells and bottom cells in perovskite-silicon tandem devices. Fraunhofer ISE’s PV-TEC research line operates an automated tester handling formats up to G12 and shingle cells. In a study, 150 IBC cells with varying efficiencies were measured, showing strong agreement between this method and traditional techniques. The development was funded by Germany’s Federal Ministry for Economic Affairs under the “NextTec”