Dislocation-Free and Atomically Flat GaN Hexagonal Microprisms for Device Applications
| Autor: | Olof Hultin, Anders Gustafsson, Rainer Timm, Maryam Khalilian, Mats-Erik Pistol, Jonas Ohlsson, Reine Wallenberg, Jonas Johansson, Jovana Colvin, Filip Lenrick, Lars Samuelson, Zhaoxia Bi |
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| Rok vydání: | 2019 |
| Předmět: |
III-V semiconductors
Materials science Annealing (metallurgy) photonics Nanowire 02 engineering and technology Nitride 010402 general chemistry 01 natural sciences GaN Nitrides law.invention Biomaterials law Lattice mismatch Naturvetenskap Phenomenological model General Materials Science Kinetically controlled Diode Wulff construction business.industry Growth substrates Device application Ultraviolet spectral range Prisms self-assembly Gallium nitride General Chemistry 021001 nanoscience & nanotechnology III-nitride Light emitting diodes 0104 chemical sciences microprisms Dislocation free High dislocation density Optoelectronics Photonics Phenomenological modeling Natural Sciences 0210 nano-technology business Biotechnology Light-emitting diode |
| Zdroj: | Small (Weinheim an der Bergstrasse, Germany). 16(30) |
| ISSN: | 1613-6829 |
| Popis: | III-nitrides are considered the material of choice for light-emitting diodes (LEDs) and lasers in the visible to ultraviolet spectral range. The development is hampered by lattice and thermal mismatch between the nitride layers and the growth substrate leading to high dislocation densities. In order to overcome the issue, efforts have gone into selected area growth of nanowires (NWs), using their small footprint in the substrate to grow virtually dislocation-free material. Their geometry is defined by six tall side-facets and a pointed tip which limits the design of optoelectronic devices. Growth of dislocation-free and atomically smooth 3D hexagonal GaN micro-prisms with a flat, micrometer-sized top-surface is presented. These self-forming structures are suitable for optical devices such as low-loss optical cavities for high-efficiency LEDs. The structures are made by annealing GaN NWs with a thick radial shell, reforming them into hexagonal flat-top prisms with six equivalents either m- or s-facets depending on the initial heights of the top pyramid and m-facets of the NWs. This shape is kinetically controlled and the reformation can be explained with a phenomenological model based on Wulff construction that have been developed. It is expected that the results will inspire further research into micron-sized III-nitride-based devices. © 2020 The Authors. Funding details: Energimyndigheten; Funding details: VetenskapsrÃ¥det, VR; Funding details: 608153; Funding details: Knut och Alice Wallenbergs Stiftelse; Funding details: Stiftelsen för Strategisk Forskning, SSF; Funding text 1: The authors would like to thank David Lindgren, Kristian Storm, and Rafal Ciechonski for their valuable inputs to this project. This research was performed at the Lund Nano Lab, a part of the MyFab facilities. The project was supported by the Swedish Research Council (VR), the Foundation for Strategic Research (SSF), the Knut and Alice Wallenberg Foundation (KAW), the Swedish Energy Agency, and Marie‐Curie FP7‐REA‐GA 608153 (PhD4energy funding). |
| Databáze: | OpenAIRE |
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