IV Measurements of Shingle Solar Cells

Due to the large variety of contacting probes, the measured IV characteristics of solar cells differ considerably depending on the contacting used. In particular, the FF heavily depends on the selected contacting layout. The number and distribution of the contact points on the cell but also the shading by the measuring probes affect the FF. To be able to determine losses due to the cutting process from host to shingle cell and cell to module losses, the impact of two different contact units installed in an inline cell tester was evaluated. With PCBTOUCH contacting, the resistance losses of the front wires must be considered, otherwise the FF losses caused by cutting will be underestimated by 0.5%abs. because the resistance contribution of the wires in the host cell measurement is significantly stronger than in the shingle cell measurement. For the universal contact probes, series resistance losses caused by the probes must also be corrected, but these do not affect the FF losses due to the cutting process, but only the absolute value of the FF.