Non-equilibrium induction of tin in germanium: towards direct bandgap Ge1-xSnx nanowires


Autoria(s): Biswas, Subhajit; Doherty, Jessica; Saladukha, Dzianis; Ramasse, Quentin; Majumdar, Dipanwita; Upmanyu, Moneesh; Singha, Achintya; Ochalski, Tomasz; Morris, Michael A.; Holmes, Justin D.
Data(s)

30/04/2016

30/04/2016

20/04/2016

26/04/2016

Resumo

The development of non-equilibrium group IV nanoscale alloys is critical to achieving new functionalities, such as the formation of a direct bandgap in a conventional indirect bandgap elemental semiconductor. Here, we describe the fabrication of uniform diameter, direct bandgap Ge1-xSnx alloy nanowires, with a Sn incorporation up to 9.2[thinsp]at.%, far in excess of the equilibrium solubility of Sn in bulk Ge, through a conventional catalytic bottom-up growth paradigm using noble metal and metal alloy catalysts. Metal alloy catalysts permitted a greater inclusion of Sn in Ge nanowires compared with conventional Au catalysts, when used during vapour-liquid-solid growth. The addition of an annealing step close to the Ge-Sn eutectic temperature (230[thinsp][deg]C) during cool-down, further facilitated the excessive dissolution of Sn in the nanowires. Sn was distributed throughout the Ge nanowire lattice with no metallic Sn segregation or precipitation at the surface or within the bulk of the nanowires. The non-equilibrium incorporation of Sn into the Ge nanowires can be understood in terms of a kinetic trapping model for impurity incorporation at the triple-phase boundary during growth.

Formato

application/pdf

Identificador

BISWAS, S., DOHERTY, J., SALADUKHA, D., RAMASSE, Q., MAJUMDAR, D., UPMANYU, M., SINGHA, A., OCHALSKI, T., MORRIS, M. A. & HOLMES, J. D. 2016. Non-equilibrium induction of tin in germanium: towards direct bandgap Ge1-xSnx nanowires. Nature Communications, 7 :11405. doi: 10.1038/ncomms11405

7

1

12

2041-1723

http://hdl.handle.net/10468/2505

10.1038/ncomms11405

Nature Communications

11405

Idioma(s)

en

Publicador

Nature Publishing Group

Relação

http://www.nature.com/ncomms/2016/160420/ncomms11405/full/ncomms11405.html

Direitos

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http://creativecommons.org/licenses/by/4.0/

Palavras-Chave #Physical sciences #Materials science #Nanotechnology #Physical chemistry
Tipo

Article (peer-reviewed)