2019/09/30 by Hung-Ling Chen, Andrea Scaccabarozzi, Romaric De Lépinau +5
Engineering · Physics and Astronomy · #Band gap #Cathodoluminescence #Characterization (materials science) #Dopant #Doping #Fermi level #GaN-based semiconductor devices and materials #Microelectronics #Semiconductor #Semiconductor Quantum Structures and Devices #Silicon and Solar Cell Technologies #Thin film #cond-mat.mtrl-sci #physics.optics
paper · pdf · doi:10.1103/physrevapplied.15.024006
published as Phys. Rev. Applied 15, 024006 (2021)
openalex created_date 2019/09/19 · openalex publication_date 2021/02/02 · arxiv created 2022/01/03 · arxiv updated 2022/01/04 · openalex updated_date 2026/08/05
Doping is a fundamental property of semiconductors and constitutes the basis of modern microelectronic and optoelectronic devices. Their miniaturization requires contactless characterization of doping with nanometer-scale resolution. Here, we use low- and room-temperature cathodoluminescence (CL) measurements to analyze p-type and n-type GaAs thin films over a wide range of carrier densities (2\ifmmode×\else\texttimes\fi1017 to 1\ifmmode×\else\texttimes\fi1019\phantom\rule0.2em0excm^\ensuremath-3). The spectral shift and broadening of CL spectra induced by shallow dopant states and band filling are the signature of doping. We fit the whole spectral lineshapes with the generalized Planck law and refined absorption models to extract the bandgap narrowing and the band tail for both doping types, and the electron Fermi level for n doping. This work provides a rigorous method for the quantitative assessment of p-type and n-type carrier densities using CL. Taking advantage of the high spatial resolution of CL, it can be used to map the doping in GaAs nanostructures, and it could be extended to other semiconductor materials.