Applied Surface Science, Vol.254, No.23, 7737-7741, 2008
Spatial resolution of imaging contaminations on the GaAs surface by scanning tunneling microscope-cathodoluminescence spectroscopy
We obtained the luminescence image of the GaAs (1 1 0) surface by scanning tunneling microscope-cathodoluminescence (STM-CL) spectroscopy, where low-energy (similar to 100 eV) electrons field emitted from the STM tip were used as a bright excitation source. The STM-CL image with high photon signal (1.25 x 10(4) cps) showed the dark image corresponding to the surface contamination in the STM image working as the nonradiative recombination centers of carriers. This dark image demonstrated the spatial resolution of about 100 nm in STM-CL spectroscopy of the GaAs (1 1 0) surface, which was determined by the field-emitted electron beam diameter. (C) 2008 Elsevier B.V. All rights reserved.