This thesis addresses the characterization of individual doped semiconductors microand nanowires by photoemission electron microscopy (XPEEM) and near field techniques : Kelvin probe force microscopy (KFM) and Scanning Capacitance Microscopy (SCM). The aim of this study is to evaluate the benefits of contactless surface methods, thanks to local work function and core level binding energy measurements, for the study of phenomena linked to doping in such objects, like for example axial uniformity. First, we highlight the importance of sample preparation required for these techniques: wires transfer methods, importance of the substrate type, and influence of previous characterization on PEEM/SCM results. Then we present two case studies addressing technological issues: Si doped gallium nitride microwires (2 μm diameter) for solid state lighting, and nanowires presenting p-n junction (100 nm diameter) for low power microelectronics. In the first case, we have performed SCM for quick identification of n doping axial heterogeneity, then performed spectroscopic XPEEM using synchrotron radiation to, first, estimate local work function and surface band bending, then clarify surface silicon incorporation highlighting growth process influence over electrically active (Si on Ga sites) and non-active doping (Si on nitrogen vacancy). Complementary measurements on both axial and radial section of wires have been led by Auger microscopy and ToF-SIMS, highlighting silicon incorporation preferentially at the surface of the microwires. Regarding p-n junctions, after partial removal of surface oxide, we have linked results obtained independently by KFM and XPEEM. Both methods highlighted a weak local work function difference between n-doped and p-doped part, partly explained by Fermi level pinning induced by surface states.
