title: Multi-quantum-well nanowire heterostructures for wavelength-controlled lasers.
abstract: 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 1-3 nm. Optical excitation of individual MQW nanowire structures yielded lasing with InGaN quantum-well composition-dependent emission from 365 to 494 nm, 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.
authors: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
authors: Fang
authors: F
authors: Qian
authors: Yat
authors: Y
authors: Li
authors: Silvija
authors: S
authors: Gradecak
authors: Hong-Gyu
authors: HG
authors: Park
authors: Yajie
authors: Y
authors: Dong
authors: Yong
authors: Y
authors: Ding
authors: Zhong Lin
authors: ZL
authors: Wang
authors: Charles M
authors: CM
authors: Lieber