Imaging of the interstitial iron concentration in crystalline silicon by measuring the dissociation rate of iron-boron pairs

We present a dynamic approach for measuring the interstitial iron concentration in boron-doped crystalline silicon using photoluminescence (PL) imaging. This camera-based technique utilizes the characteristic dependence of the dissociation rate of iron-boron pairs on the interstitial iron concentration. We determine the dissociation rate by measuring the time-dependent PL signal after complete association of iron-boron pairs in the sample. Since we are only interested in the time dependence of the PL signal, we are able to generate images of the interstitial iron concentration in absolute units without any calibration and without knowing the recombination properties of the interstitial iron or iron-boron pairs.