Bismuth surfactant-enhanced III-As epitaxy on GaAs(111)A

Abstract Quantum dot (QD) growth on high (c 3v ) symmetry GaAs{111}
surfaces holds promise for efficient entangled photon sources. Unfortunately,
homoepitaxy GaAs{111} surfaces suffers from surface roughness/defects
and InAs deposition does not natively support Stranski–Krastanov (SK) QD
growth. Surfactants have been identified as effective tools to alter the epitaxial
growth process of III-V materials, however, their use remains unexplored on
GaAs{111}. Here, we investigate Bi a surfactant in III-As molecular beam
epitaxy (MBE) GaAs(111)A substrates, demonstrating that can eliminate
surface defects/hillocks GaAs and (Al,Ga)As layers, yielding atomically-smooth
hillock-free with RMS roughness values low 0.13 nm. Increasing Bi
fluxes are found result smoother is observed increase
adatom diffusion. The also shown trigger morphological
transition InAs/GaAs(111)A films, directing 2D layer rearrange into
3D nanostructures, which promising candidates high-symmetry quantum
dots. desorption activation energy (U Des was measured
by reflection electron diffraction (RHEED), U = 1.7 ±
0.4 eV. These results illustrate potential surfactants and
will help pave way platform technological applications
including quantum photonics.