TY - JOUR

T1 - Formation of Hexagonal Ge Stripes on the Side Facets of AlGaAs Nanowires

T2 - Implications for Near-Infrared Detectors

AU - Ilkiv, Igor V.

AU - Kotlyar, Konstantin P.

AU - Kirilenko, Demid A.

AU - Osipov, Andrey V.

AU - Soshnikov, Ilya P.

AU - Mikushev, Sergey V.

AU - Dubrovskii, Vladimir G.

AU - Cirlin, George E.

N1 - Publisher Copyright: © 2021 American Chemical Society

PY - 2021/7/14

Y1 - 2021/7/14

N2 - Obtaining hexagonal Ge is a great challenge and has previously been achieved by transferring the wurtzite phase of GaAs nanowires, where Ge forms a conformal shell around a nanowire. Here, we demonstrate hexagonal Ge stripes of 6 nm height and 17 nm width, which decorate 25 nm-wide side facets of wurtzite AlGaAs nanowires. Ge shells are grown by molecular beam epitaxy at a low temperature of 320 °C. The hexagonal structure of Ge is revealed by Raman spectroscopy and high-resolution transmission electron microscopy (TEM), the latter shows the pure 2H phase. The formation of Ge stripes on the side facets of AlGaAs nanowires is demonstrated by scanning TEM in the angular annular dark-field mode and explained within an energetic model. These results show a possibility of forming 2H wire-like Ge structures with tunable geometry using AlGaAs nanowire templates. Such structures can be exploited for direct band gap engineering and quantum confinement effects and used in near-infrared optoelectronics based on nanostructured Ge.

AB - Obtaining hexagonal Ge is a great challenge and has previously been achieved by transferring the wurtzite phase of GaAs nanowires, where Ge forms a conformal shell around a nanowire. Here, we demonstrate hexagonal Ge stripes of 6 nm height and 17 nm width, which decorate 25 nm-wide side facets of wurtzite AlGaAs nanowires. Ge shells are grown by molecular beam epitaxy at a low temperature of 320 °C. The hexagonal structure of Ge is revealed by Raman spectroscopy and high-resolution transmission electron microscopy (TEM), the latter shows the pure 2H phase. The formation of Ge stripes on the side facets of AlGaAs nanowires is demonstrated by scanning TEM in the angular annular dark-field mode and explained within an energetic model. These results show a possibility of forming 2H wire-like Ge structures with tunable geometry using AlGaAs nanowire templates. Such structures can be exploited for direct band gap engineering and quantum confinement effects and used in near-infrared optoelectronics based on nanostructured Ge.

KW - AlGaAs nanowires

KW - hexagonal Ge stripe

KW - molecular beam epitaxy

KW - side facets

KW - transmission electron microscopy

KW - ORIGIN

KW - GERMANIUM

KW - EMISSION

KW - GAAS

KW - QUANTUM DOTS

UR - http://www.scopus.com/inward/record.url?scp=85111520859&partnerID=8YFLogxK

U2 - 10.1021/acsanm.1c01266

DO - 10.1021/acsanm.1c01266

M3 - Article

AN - SCOPUS:85111520859

VL - 4

SP - 7289

EP - 7294

JO - ACS Applied Nano Materials

JF - ACS Applied Nano Materials

SN - 2574-0970

IS - 7

ER -