First-principles study of (InAs)1/(GaSb)1 superlattice atomic chains

Abstract

The atomic structure, the mechanical properties, the electronic band structure, and the phonon structure of (InAs)1/(GaSb)1 superlattice atomic chain are investigated by first-principles pseudopotential plane wave method, and the quantum transport properties are also calculated by the density functional theory numerical atomic orbit pseudopotential method in combination with nonequilibrium Green's function formalism. Compared with two-dimensional layer structural (InAs)1/(GaSb)1 superlattice, the (InAs)1/(GaSb)1 superlattice atomic chains have obviously different band structures, and represent metal energy band characteristics in certain conditions. The calculated mechanical strength of (InAs)1/(GaSb)1 superlattice atomic chains indicates that such structures can sustain the strain as high as =0.19. The structural stability of (InAs)1/(GaSb)1 superlattice atomic chains is investigated by full Brillouin zone analysis for phonon structure. The electron transport calculations for (InAs)1/(GaSb)1 superlattice atomic chain segments in between Al electrodes show that the conductance exhibits nontrivial features as the chain length or strain is varied. The calculated optical absorption spectra represent precipitous cutoff absorptions in infrared regime, and the cutoff wavelength varies with chain structure. InAs/GaSb superlattice atomic chains are predicted to be applied to infrared optoelectronic nanodevices, modifying optoelectronic response wavelength range by changing the structures of superlattice atomic chains.