Synchrotron microanalysis techniques applied to potential photovoltaic materials

X-ray synchrotron radiation techniques are used to characterize photovoltaic-related semiconductors. Micro-X-ray-fluorescence and X-ray beam induced current mapping of multicrystalline silicon photovoltaic cells show metallic impurities accumulating at the interface of crystallographic defects, and current variations over the cell that are attributed to bulk defects and structural variation of the silicon. Similarly, studies on a single-crystal GaAs using X-ray fluorescence and X-ray excited optical luminescence show an inhomogeneous As distribution correlated with the photoluminescence signal, with higher As concentration regions having stronger photoluminescence signal. Both examples show how the combination of synchrotron microanalysis techniques can contribute to a better understanding of the optical properties of photovoltaic materials.