Comparing Microwave Detected Photoconductance, Quasi Steady State Photoconductance and Photoluminiscence Imaging for Iron Analysis in Silicon

Interstitial iron (Fei) is one of the most prominent metallic impurities in crystalline silicon, as it is fast diffusive and highly recombination-active. Its accurate detection is crucial for quality control during solar cell production as iron contamination can significantly limit solar cell efficiency. This work gives a qualitative and quantitative comparison of iron characterization tools including QSSPC (quasi steady state photoconductance), PLI (Photoluminescence Imaging) and MDP (Microwave detected photo conductance). The detection limits, feasibility and accuracy of each tool for iron detection are investigated. In principle, despite of different injection regimes, the absolute iron concentration measured on the different characterising tools is in the same order of magnitude with very good qualitative and quantitative correlation. With the results obtained, the comparison of QSSPC, PLI and MDP showed a mean deviation of 20%.