Showing papers by "Venkatesh Narayanamurti published in 1996"
TL;DR: Single InAs self-assembled quantum dots buried spatially beneath a Au/GaAs interface are probed for the first time using the imaging and spectroscopic modes of ballistic electron emission microscopy (BEEM).
Abstract: Single InAs self-assembled quantum dots buried spatially beneath a Au/GaAs interface are probed for the first time using the imaging and spectroscopic modes of ballistic electron emission microscopy (BEEM). BEEM images show enhanced current through each dot. Spectra taken with the tip positioned on a dot show shifted current thresholds when compared with the off dot spectra, which are essentially the same as those of Au on bulk GaAs. Shifts in the $\ensuremath{\gamma}$ and $L$ conduction band thresholds are attributed to strain in the GaAs cap layer. Fine structure below the $\ensuremath{\gamma}$ threshold is consistent with resonant tunneling through zero-dimensional states within the quantum dots.
65 citations
TL;DR: In this paper, an ordered GaInP/GaAs heterostructures were studied using ballistic-electron-emission microscopy (BEEM) and the conduction band offset was found to decrease with increasing order.
Abstract: Ordered‐GaInP/GaAs heterostructures have been studied using ballistic‐electron‐emission microscopy (BEEM). The GaInP/GaAs conduction band offset was found to decrease with increasing order. Samples were grown simultaneously on different misoriented substrates to vary the degree of order in the GaInP. Concurrent scanning tunneling microscopy and BEEM images show ridge structures in the topography and contrast in the BEEM current that may correspond to ordered domains in the GaInP. Room temperature conduction band offsets of 137 and 86 meV were measured using BEEM spectroscopy for GaInP with 2 K band gaps of 1.97 and 1.89 eV, respectively.
47 citations
TL;DR: In this article, the authors reported ballistic electron-emission microscopy (BEEM) imaging and spatially resolved spectroscopy of InxGa1−xAs/GaAs misfit dislocations 800 A below the surface.
Abstract: We report ballistic‐electron‐emission microscopy (BEEM) imaging and spatially resolved spectroscopy of InxGa1−xAs/GaAs misfit dislocations 800 A below the surface. Majority‐carrier scattering by a fraction of misfit dislocations was seen to locally reduce the BEEM current and to give logarithmic spatial dependence, which suggests charging of the dislocation cores.
9 citations