Recombination current and series resistance imaging of solar cells by combined luminescence and lock-in thermography

We perform recombination current and series resistance imaging on large-area crystalline silicon solar cells using a combined analysis of camera-based dark lock-in thermography (DLIT) and electroluminescence (EL) imaging. The solar cells are imaged both by DLIT and EL under identical operating conditions. The quantitative analysis of the DLIT measurement produces an image of the local heating power and the EL picture results in an image of the local cell voltage. Combining the two images pixel by pixel allows us to calculate images of the local recombination current and the local series resistance of the solar cell.