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arXiv · 1607.03397

Quenching of the luminescence intensity of GaN nanowires under electron beam exposure: Impact of C adsorption on the exciton lifetime

Jonas Lähnemann·Timur Flissikowski·Martin Wölz·Lutz Geelhaar·Holger T. Grahn·Oliver Brandt·Uwe Jahn
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Abstract

Electron irradiation of GaN nanowires in a scanning electron microscope strongly reduces their luminous efficiency as shown by cathodoluminescence imaging and spectroscopy. We demonstrate that this luminescence quenching originates from a combination of charge trapping at already existing surface states and the formation of new surface states induced by the adsorption of C on the nanowire sidewalls. The interplay of these effects leads to a complex temporal evolution of the quenching, which strongly depends on the incident electron dose per area. Time-resolved photoluminescence measurements on electron-irradiated samples reveal that the carbonaceous adlayer affects both the nonradiative and the radiative recombination dynamics.

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Jonas Lähnemann, Timur Flissikowski, Martin Wölz, Lutz Geelhaar, Holger T. Grahn, Oliver Brandt, Uwe Jahn. 2017-10-12. Quenching of the luminescence intensity of GaN nanowires under electron beam exposure: Impact of C adsorption on the exciton lifetime. https://doi.org/10.1088/0957-4484%2F27%2F45%2F455706

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