Molecular beam epitaxy growth of GaAsBi using As2 and As4

Richards, Robert D.; Bastiman, F.; Hunter, C. J.; Mendes, D.; Mohmad, Abdul Rahman; Roberts, J.S.; David, J.P.R.

doi:10.1016/j.jcrysgro.2013.12.008

Cited by 56 publications

(52 citation statements)

References 28 publications

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“…First, if the As flux is increased, the exchange process will occur faster and consequently lead to a lower incorporation of Bi, in agreement with previous experiments [25,27,50]. Second, because As 2 in the trench of Bi surface has a diffusion barrier of 0.36 eV and an exchange barrier of 0.65 eV, the times of hopping before each exchange process can be approximated by…”

Section: E Possible Growth Processessupporting

confidence: 86%

First-principles studies on molecular beam epitaxy growth ofGaAs1−xBix

Luo

Yang

et al. 2015

Phys. Rev. B

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We investigate the molecular beam epitaxy (MBE) growth of GaAs 1-x Bi x film using density functional theory with spin-orbit coupling to understand the growth of this film, especially the mechanisms of Bi incorporation. We study the stable adsorption structures and kinetics of the incident MBE species (As 2 molecule, Ga atom, Bi atom, and Bi 2 molecule) on the (2×1)-Ga sub ||Bi surface and a proposed q(1×1)-Ga sub ||AsAs surface, where Ga sub ||XY refers to a Ga-terminated GaAs(001) substrate with surface layers of X and Y. The q(1×1)-Ga sub ||AsAs surface has a quasi-(1×1) As layer above the Ga-terminated GaAs substrate and a randomly-oriented As dimer layer on top. We obtain the desorption and diffusion barriers of the adsorbed MBE species and also the reaction barriers of three key processes related to Bi evolution, namely, Bi incorporation, As/Bi exchange, and Bi clustering. The results help explain the experimentally observed dependence of Bi incorporation on the As/Ga ratio and growth temperature. Furthermore, we find that As 2 exchange with Bi of the (2×1)-Ga sub ||Bi surface is a key step controlling the kinetics of the Bi incorporation. Finally, we explore two possible methods to enhance the Bi incorporation, namely, replacing the MBE growth mode from co-deposition of all fluxes with a sequential deposition of fluxes and applying asymmetric in-plane strain to the substrate.

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Section: E Possible Growth Processessupporting

confidence: 86%

First-principles studies on molecular beam epitaxy growth ofGaAs1−xBix

Luo

Yang

et al. 2015

Phys. Rev. B

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“…7 In the usual growth temperature range of GaAs, 500-600°C, the Bi incorporation is nearly zero, which has been confirmed by both experiments 8 and theoretical claculations. 9 To enhance the Bi incorporation, growth temperatures as low as 300-400°C are widely used to decelerate the growth dynamics that lead to low Bi incorporation.…”

Section: Introductionmentioning

confidence: 55%

Understanding and reducing deleterious defects in the metastable alloy GaAsBi

et al. 2017

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Technological applications of novel metastable materials are frequently inhibited by abundant defects residing in these materials. Using first-principles methods, we investigate the defect thermodynamics and phase segregation in the technologically important metastable alloy GaAsBi. Our calculations predict defect energy levels in good agreement with those from numerous previous experiments and clarify the defect structures giving rise to these levels. We find that vacancies in some charge states become metastable or unstable with respect to antisite formation, and this instability is a general characteristic of zincblende semiconductors with small ionicity. The dominant point defects that degrade the electronic and optical performances are predicted to be As Ga , Bi Ga , As Ga +Bi As , Bi Ga +Bi As , V Ga and V Ga +Bi As , of which the first four and last two defects are minority-electron and minority-hole traps, respectively. V Ga is also observed to have a critical role in controlling metastable Bi supersaturation by mediating Bi diffusion and clustering. To reduce the influences of these deleterious defects, we suggest shifting the growth away from an As-rich condition and/or using hydrogen passivation to reduce the minority-carrier traps. We expect this work to aid in the applications of GaAsBi for novel electronic and optoelectronic devices and to illuminate the control of deleterious defects in other metastable materials.

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“…The optimum growth control for Bi incorporatin in GaAs without forming Ga or Bi droplets is less strict when using As4 other than As2 as the As source. Richards et al [137] made a systematic study upon the influence of As2 and As4 on GaAsBi growth and showed that for the same Bi incorporation, the required As2:Ga atomic flux ratio is much lower than that of As4:Ga. As2 dimers effectively provide As atoms that can be directly incorporated into GaAs, while for As4 tetramers the thermal cracking efficiency into As is low and a much broad range of As:Ga flux ratio is permitted for Bi incorporation. This indicates that the optimum growth procedure is easy to achieve under As4 condition.…”

Section: Growth Ratementioning

confidence: 99%

Novel Dilute Bismide, Epitaxy, Physical Properties and Device Application

Wang

Zhang

et al. 2017

Crystals

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Abstract:Dilute bismide in which a small amount of bismuth is incorporated to host III-Vs is the least studied III-V compound semiconductor and has received steadily increasing attention since 2000. In this paper, we review theoretical predictions of physical properties of bismide alloys, epitaxial growth of bismide thin films and nanostructures, surface, structural, electric, transport and optic properties of various binaries and bismide alloys, and device applications.

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Molecular beam epitaxy growth of GaAsBi using As2 and As4

Cited by 56 publications

References 28 publications

First-principles studies on molecular beam epitaxy growth ofGaAs1−xBix

First-principles studies on molecular beam epitaxy growth ofGaAs1−xBix

Understanding and reducing deleterious defects in the metastable alloy GaAsBi

Novel Dilute Bismide, Epitaxy, Physical Properties and Device Application

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