New opportunities to study defects by soft X-ray absorption fine structure

X-ray absorption fine structure can determine the local structure of most atoms in the periodic table. The great recent improvements in the performance of synchrotron radiation sources and techniques and advances in the simulations of the spectra have opened new opportunities, especially in the study of dilute systems in the soft X-ray range. In this contribution we will show some recent results that demonstrate how semiconductor physics may greatly benefit from such progress. In fact, doping or alloying of semiconductors with light elements, that have K absorption edges in the soft X-ray range, is widely employed to tune semiconductor properties. X-ray absorption fine structure investigations on such systems can give an important contribution towards the understanding and optimization of technological processes.