Dislocation-Free and Atomically Flat GaN Hexagonal Microprisms for Device ApplicationsShow others and affiliations
2020 (English)In: Small, ISSN 1613-6810, E-ISSN 1613-6829, Vol. 16, no 30, article id 1907364Article in journal (Refereed) Published
Abstract [en]
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.
Place, publisher, year, edition, pages
Wiley-VCH Verlag , 2020. Vol. 16, no 30, article id 1907364
Keywords [en]
GaN, III-nitride, microprisms, photonics, self-assembly, III-V semiconductors, Lattice mismatch, Light emitting diodes, Nitrides, Prisms, Device application, Dislocation free, Growth substrates, High dislocation density, Kinetically controlled, Phenomenological modeling, Ultraviolet spectral range, Wulff construction, Gallium nitride
National Category
Natural Sciences
Identifiers
URN: urn:nbn:se:ri:diva-45357DOI: 10.1002/smll.201907364Scopus ID: 2-s2.0-85087170705OAI: oai:DiVA.org:ri-45357DiVA, id: diva2:1454221
Note
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).
2020-07-152020-07-152021-06-18Bibliographically approved