Growth and optical properties of direct band gap Ge/Ge0.87SN0.13 Core/Shell nanowire arrays

Article

Assali, S., Dijkstra, A., Li, A., Kölling, S., Verheijen, M.A., Gagliano, L., von den Driesch, N., Buca, D., Koenraad, P.M., Haverkort, J.E.M. & Bakkers, E.P.A.M. (2017). Growth and optical properties of direct band gap Ge/Ge0.87SN0.13 Core/Shell nanowire arrays. Nano Letters, 17(3), 1538-1544. In Scopus Cited 3 times.

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Abstract

 

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 Ge0.87Sn0.13 shell 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