LUMINESCENCE IN SCANNING TUNNELING MICROSCOPY ON III-V NANOSTRUCTURES

Using electroluminescence associated with scanning tunneling microscope in Al(x)Ga(1-x)As heterostructures, we show that: (a) luminescence due to recombination can be induced within single quantum wells of dimensions down to a few nm and can also be used to image them, (b) the energy of bulk bands can be determined, and (c) transport parameters can be measured, e.g., the thermalization length and the diffusion length of minority electrons. This technique opens up new possibilities for the study and characterization of semiconductors and devices-including the possibility of studying surface states and single trapping centers associated with lattice defects, impurities, chemisorbed species, etc.