Growth mode of tensile-strained Ge quantum dots grown by molecular beam epitaxy

• Growth mode of tensile-strained Ge quantum dots on different III-V buffers by molecular beam epitaxy is studied by a combination of reflection high-energy electron diffraction, atomic force microscopy and transmission electron microscopy. The Ge-QDs growth on the InAlAs buffer lattice matched to InP and on InAs buffer on GaSb follows the Volmer-Weber growth mode with round Ge QDs and no Ge wetting layer, while it obeys the Stranski-Krastanov growth mode on GaSb, AlSb and AlGaSb on GaSb substrates, showing rectangular shaped platelets and a clear Ge wetting layer. The discovery of the Volmer-Weber growth mode is essential to avoid forming a wetting layer and the subsequent antiphase-domain defects when capping III-Vs on Ge-QDs, important for potential optoelectronic applications.

Ämnesord

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Nyckelord

growth mode

tensile-strained

germanium

quantum dots

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)