Carlos A. Pérez is currently researcher at the Carnaúba group of the LNLS. His main fields of interests are atomic and molecular physics, general physics, x-ray and synchrotron instrumentation, synchrotron radiation applications in physics and biology. Current research involves the use of several synchrotron-based x-ray analytical methods for trace elements studies in biological tissues focusing on toxicity and bio- and phytoremediation, soil science and plant analysis, metal impurities in semiconductor (DMS and Photo-catalyzer) and structural characterization of material by X-ray Resonant Raman Scattering (XRRS).