Probing individual nanostructures with STM-induced light emission

We present the results of our latest work using the spectroscopy of light e mitted by a sample under the scanning tunneling microscope (STM). For the q uantum wells in AlGaAs/GaAs layered structures, we have demonstrated that t he emission spectra from individual wells can be measured by this method an d that the minority carrier diffusion length can be estimated in real space . Furthermore, we have discovered that the emission linewidth depends on th e location even within an individual well. On the reconstructed Au(110)-(2 x 1) surface, the emission from an atomically localized electronic transiti on in the valley between the atomic rows was found. (C) 2001 Elsevier Scien ce Ltd. All rights reserved.