Metal Induced Recombination Parameter Extraction using High Resolution Photoluminescence Imaging for Silicon Solar Cells

Metal induced recombination (i.e., contact recombination) is a significant loss mechanism for homojunction crystalline silicon solar cells. In this work, a method is proposed to extract the metal induced recombination parameters using high- resolution photoluminescence PL imaging. By calculating the voltage distribution profile between fingers, the total current flow from the semiconductor to the finger, per area, can be obtained. The total recombination current at the semiconductor area and the metal contact area are then calculated and used to calculate the reverse saturation current for each region. The metal induced reverse saturation current $(j_{0m})$ is then obtained. This measurement allows the extraction of $j_{0m}$ on finished solar cells without the need to make special metal test structures. This is a big advantage over existing methods.