Rational design and synthesis of nanowires with increasingly complex structures can yield enhanced and/or novel electronic and photonic functions. For example, Ge/Si core/shell nanowires have exhibited substantially higher performance as field-effect transistors and low-temperature quantum devices compared with homogeneous materials, and nano-roughened Si nanowires were recently shown to have an unusually high thermoelectric figure of merit. Here, we report the first multi-quantum-well (MQW) core/shell nanowire heterostructures based on well-defined III-nitride materials that enable lasing over a broad range of wavelengths at room temperature. Transmission electron microscopy studies show that the triangular GaN nanowire cores enable epitaxial and dislocation-free growth of highly uniform (InGaN/GaN)(n) quantum wells with n≤3, 13 and 26 and InGaN well thicknesses of 1-3nm. Optical excitation of individual MQW nanowire structures yielded lasing with InGaN quantum-well composition-dependent emission from 365 to 494nm, and threshold dependent on quantum well number, n. Our work demonstrates a new level of complexity in nanowire structures, which potentially can yield free-standing injection nanolasers.
Bibliographical noteFunding Information:
The authors thank C. J. Barrelet and Y. N. Wu for helpful discussions, P. Stadelmann for providing JEMS simulation software, R. Schalek for help with ultramicrotomy and A. J. Garratt-Reed for assistance in EDS elemental mapping measurements. This work was supported by the Air Force Office of Scientific Research (C.M.L.) and the Department of Energy Basic Energy Sciences, DE-FG02-07ER46394, (Z.L.W.).
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering