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Nonpolar InGaN/GaN Core–Shell Single Nanowire Lasers

Research paper by Changyi Li, Jeremy B. Wright, Sheng Liu, Ping Lu, Jeffrey J. Figiel, Benjamin Leung, Weng W. Chow, Igal Brener, Daniel D. Koleske, Ting-Shan Luk, Daniel F. Feezell, S. R. J. Brueck, George T. Wang

Indexed on: 25 Jan '17Published on: 24 Jan '17Published in: Nano Letters



Abstract

We report lasing from nonpolar p-i-n InGaN/GaN multi-quantum well core–shell single-nanowire lasers by optical pumping at room temperature. The nanowire lasers were fabricated using a hybrid approach consisting of a top-down two-step etch process followed by a bottom-up regrowth process, enabling precise geometrical control and high material gain and optical confinement. The modal gain spectra and the gain curves of the core–shell nanowire lasers were measured using micro-photoluminescence and analyzed using the Hakki-Paoli method. Significantly lower lasing thresholds due to high optical gain were measured compared to previously reported semipolar InGaN/GaN core–shell nanowires, despite significantly shorter cavity lengths and reduced active region volume. Mode simulations show that due to the core–shell architecture, annular-shaped modes have higher optical confinement than solid transverse modes. The results show the viability of this p-i-n nonpolar core–shell nanowire architecture, previously investigated for next-generation light-emitting diodes, as low-threshold, coherent UV–visible nanoscale light emitters, and open a route toward monolithic, integrable, electrically injected single-nanowire lasers operating at room temperature.

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