Growth and Optical Properties of Direct Band Gap Ge/Ge0.87Sn0.13Core/Shell Nanowire Arrays.
Group IV semiconductor optoelectronic devices are now possible by using strain-free direct band gap GeSn alloys grown on a Ge/Si virtual substrate with Sn contents above 9%. Here, we demonstrate the growth of Ge/GeSn core/shell nanowire arrays with Sn incorporation up to 13% and without the formation of Sn clusters. The nanowire geometry promotes strain relaxation in the Ge0.87Sn0.13shell and limits the formation of structural defects. This results in room-temperature photoluminescence centered at 0.465 eV and enhanced absorption above 98%. Therefore, direct band gap GeSn grown in a nanowire geometry holds promise as a low-cost and high-efficiency material for photodetectors operating in the short-wave infrared and thermal imaging devices.
Department of Applied Physics, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands.
S
0000-0002-3919-9112
S
Assali
Department of Applied Physics, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands.
A
A
Dijkstra
Department of Applied Physics, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands.|Kavli Institute of Nanoscience, Delft University of Technology , 2600 GA Delft, The Netherlands.|Beijing Key Lab of Microstructure and Property of Advanced Materials, Beijing University of Technology , Pingleyuan 100, Beijing 100024, P. R. China.
A
A
Li
Department of Applied Physics, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands.
S
0000-0002-6606-9110
S
Koelling
Department of Applied Physics, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands.|Philips Innovation Laboratories Eindhoven , High Tech Campus 11, 5656AE Eindhoven, The Netherlands.
M A
MA
Verheijen
Department of Applied Physics, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands.
L
0000-0003-4214-8639
L
Gagliano
Peter Gruenberg Institute 9 (PGI 9) and JARA-Fundamentals of Future Information Technologies , Forschungszentrum Juelich, 52428 Juelich, Germany.
N
0000-0003-0169-6110
N
von den Driesch
Peter Gruenberg Institute 9 (PGI 9) and JARA-Fundamentals of Future Information Technologies , Forschungszentrum Juelich, 52428 Juelich, Germany.
D
D
Buca
Department of Applied Physics, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands.
P M
PM
Koenraad
Department of Applied Physics, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands.
J E M
JE
Haverkort
Department of Applied Physics, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands.|Kavli Institute of Nanoscience, Delft University of Technology , 2600 GA Delft, The Netherlands.
E P A M
0000-0002-8264-6862
EP
Bakkers
Semiconductor nanowire; absorption; direct band gap; germanium tin; photoluminescence