title: Epitaxial growth of InGaN nanowire arrays for light emitting diodes.
abstract: Significant synthetic challenges remain for the epitaxial growth of high-quality InGaN across the entire compositional range. One strategy to address these challenges has been to use the nanowire geometry because of its strain relieving properties. Here, we demonstrate the heteroepitaxial growth of In(x)Ga(1-x)N nanowire arrays (0.06 ≤ x ≤ 0.43) on c-plane sapphire (Al(2)O(3)(001)) using a halide chemical vapor deposition (HCVD) technique. Scanning electron microscopy and X-ray diffraction characterization confirmed the long-range order and epitaxy of vertically oriented nanowires. Structural characterization by transmission electron microscopy showed that single crystalline nanowires were grown in the ⟨002⟩ direction. Optical properties of InGaN nanowire arrays were investigated by absorption and photoluminescence measurements. These measurements show the tunable direct band gap properties of InGaN nanowires into the yellow-orange region of the visible spectrum. To demonstrate the utility of our HCVD method for implementation into devices, LEDs were fabricated from In(x)Ga(1-x)N nanowires epitaxially grown on p-GaN(001). Devices showed blue (x = 0.06), green (x = 0.28), and orange (x = 0.43) electroluminescence, demonstrating electrically driven color tunable emission from this p-n junction.
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, United States.
authors.forename: Christopher
authors.initials: C
authors.lastname: Hahn
authors.forename: Zhaoyu
authors.initials: Z
authors.lastname: Zhang
authors.forename: Anthony
authors.initials: A
authors.lastname: Fu
authors.forename: Cheng Hao
authors.initials: CH
authors.lastname: Wu
authors.forename: Yun Jeong
authors.initials: YJ
authors.lastname: Hwang
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Gargas
authors.forename: Peidong
authors.initials: P
authors.lastname: Yang
mesh_terms: D003460:Crystallization / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005708:Gallium / Q000737:chemistry*; D007204:Indium / Q000737:chemistry*; D008029:Lighting / Q000295:instrumentation*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012666:Semiconductors
chemical_list: D007204:Indium; C473348:gallium nitride; D005708:Gallium; C513701:indium nitride