Structure and electronic spectroscopy of steps on GaAs(110) surfaces

Abstract

Steps on GaAs(110) surfaces, with step-normal vectors parallel to [001], are studied by scanning tunneling microscopy and spectroscopy. Two possible orientations of the steps occur, with outward normal vectors of [001] or [ 1 00 ], which in simple bulk-terminated form have Ga (cations) or As (anions) on their edges, respectively. The latter type of step in n-type or undoped material is found to retain its bulk-terminated form. A band of states is observed extending out from the valence band, associated with the dangling bonds of the terminating As atoms. It is argued that compensation of the dangling bonds on the step edges is the driving force for the step structure, producing reconstruction of the step edges in certain cases.

Intrinsic bandgap of cleaved ZnO(112¯) surfaces

“…As a result, the tunneling spectra exhibit additional current contributions, within the voltage interval corresponding to the fundamental bandgap. 25 Similar defect-induced currents were previously observed on GaNð10 10Þ and on InNð11 20Þ cleavage surfaces. 21,23 In these cases, the defect states could only be observed at negative voltages.…”

Band offsets at zincblende-wurtzite GaAs nanowire sidewall surfaces

“…GaAs(110): The valence band (VB) is seen at negative voltages and the conduction band (CB) at positive voltages. 29 Both bands are separated by an apparent band gap defined as the region where the tunneling current reaches the experimental noise level. Its width of about 1.5 eV is consistent with the bulk band gap of GaAs.…”

Formation of carbon films as the subgate dielectric of GaAs microcircuits on Si-substrates

“…2): E(π max )=9 eV for U acc =3 kV, E(π max )=9.5 eV for U acc =8 kV. Thus, the reduction of the graphite cluster size leads to a significant increase in the specific resistance to 10 11 Ω•cm and activation energy from 0.4 to 1 eV. а b Fig.…”

“…Today, special attention is focused on the architecture of structures for the LSI of submicron range [7,8]. It is the architecture that qualitatively expresses the issue of technology: the growth of epistructures, the formation of functional layers and circuitry [9,10].…”