Doping, a fundamental property of semiconductor devices can be measured at nanoscale thanks to long term developments made by IPVF-C2N researchers. In a twin papers published in Phys. Rev. Applied they report how to calibrate cathodeluminescence (CL) measurements to analyze p-type and n-type GaAs thin films over a wide range of carrier concentrations (2×1017 to 1×1019 cm-3). Then, they applied this calibration to analyze the doping concentration profiles in GaAs NWs. High-resolution maps of the hole concentration demonstrate the homogeneous doping in the pure zincblende segment of the NW. For Si-doped GaAs NWs, the electron Fermi level and the full width at half maximum of low-temperature CL spectra are used to assess the electron concentration to approximately 3 × 1017 to 6 × 1017 cm-3. These findings confirm the difficulty in obtaining highly doped n-type GaAs NWs, maybe due to doping compensation. The method developed in this work can be extended to other semiconductor materials.
References: 1. “Quantitative Assessment of Carrier Density by Cathodo-luminescence. I. GaAs thin films and modeling”,Phys. Rev. Applied 15, 024006 (2021). 2. “Quantitative Assessment of Carrier Density by Cathodo-luminescence. II. GaAs nanowires”,Phys. Rev. Applied 15, 024007 (2021).