Self-assembled nanodisks in coaxial GaAs/GaAsBi/GaAs core–multishell nanowires

Abstract

The formation of self-assembled nanodisks open up new avenue for designing novel quantum structures by utilizing a dilute bismide.

Lattice dynamics and carrier recombination in GaAs/GaAsBi nanowires

“…These changes in NW morphology re ect complex effects of Bi on the NW growth as was discussed in detail in Ref. [21,25,27,30].…”

“…According to the performed transmission microscopy measurements, all NWs have ZB crystal structure with minor WZ inclusions [27,30].…”

“…This promotes changes of the crystal structure of thin GaAs NWs from wurtzite (WZ) to zinc blende (ZB) upon Bi presence [20] and also leads to branching in ZB GaAs/GaAsBi core/shell NWs [25]. When incorporated, some of Bi atoms were shown to spontaneously segregate at twin planes forming optically active quantum dots [27]. In addition, a red shift of the absorption edge [28], indicative for the alloy formation, and a red shift of the emission spectra accompanied by a broadening of the emission linewidth were reported [21,29].…”

Wafer-scale integration of GaAs/AlGaAs core–shell nanowires on silicon by the single process of self-catalyzed molecular beam epitaxy

“…100 nm; STEM images were obtained in both BF and HAADF modes. 44 X-ray diffraction (XRD) measurements were conducted with a Malvern Panalytical X'Pert MRD system equipped with a graded parabolic X-ray mirror with a four-bounce Ge(220) monochromator and Cu Ka 1 radiation. Symmetric q-2q scans were performed with a three-bounce Ge(220) analyzer and a Xe proportional detector around the Si(111) reection.…”

The optical gain of GaAs1−x−y N x Bi y nanowires under the [100] direction uniaxial stress

“…8,9) Moreover, the large spin-orbit splitting energy is also beneficial to suppress the Auger recombination and IVBA effect of GaAsBi-based devices. 10,11) GaAsBi nanowires become particularly important and have been widely fabricated experimentally, [12][13][14] since both the above advantages of GaAsBi alloy and the quasi one-dimensional characteristics of nanowires are utilized. However, the recent theoretical study using 14-band k•p model demonstrates that the joint uniaxial stresses should be exerted along [100] and [001] directions (x and z directions) simultaneously to redshift the gain peak position of GaAsBi nanowires to the optical communication band.…”