| Autor: |
Cameron D; Department of Physics, Scottish Universities Physics Alliance (SUPA), University of Strathclyde, Glasgow G4 0NG, United Kingdom., Coulon PM; Department of Electrical & Electronic Engineering, University of Bath, Bath BA2 7AY, United Kingdom.; Centre de Recherche sur l'Hétéro-Epitaxie et ses Applications (CRHEA)-Centre National de la Recherche Scientifique (CNRS), Rue Bernard Grégory, 06560 Valbonne, France., Fairclough S; Department of Materials Science and Metallurgy, University of Cambridge, CB3 OFS Cambridge, United Kingdom., Kusch G; Department of Materials Science and Metallurgy, University of Cambridge, CB3 OFS Cambridge, United Kingdom., Edwards PR; Department of Physics, Scottish Universities Physics Alliance (SUPA), University of Strathclyde, Glasgow G4 0NG, United Kingdom., Susilo N; Institute of Solid State Physics, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany., Wernicke T; Institute of Solid State Physics, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany., Kneissl M; Institute of Solid State Physics, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany., Oliver RA; Department of Materials Science and Metallurgy, University of Cambridge, CB3 OFS Cambridge, United Kingdom., Shields PA; Department of Electrical & Electronic Engineering, University of Bath, Bath BA2 7AY, United Kingdom., Martin RW; Department of Physics, Scottish Universities Physics Alliance (SUPA), University of Strathclyde, Glasgow G4 0NG, United Kingdom. |
| Abstrakt: |
Existing barriers to efficient deep ultraviolet (UV) light-emitting diodes (LEDs) may be reduced or overcome by moving away from conventional planar growth and toward three-dimensional nanostructuring. Nanorods have the potential for enhanced doping, reduced dislocation densities, improved light extraction efficiency, and quantum wells free from the quantum-confined Stark effect. Here, we demonstrate a hybrid top-down/bottom-up approach to creating highly uniform AlGaN core-shell nanorods on sapphire repeatable on wafer scales. Our GaN-free design avoids self-absorption of the quantum well emission while preserving electrical functionality. The effective junctions formed by doping of both the n-type cores and p-type caps were studied using nanoprobing experiments, where we find low turn-on voltages, strongly rectifying behaviors and significant electron-beam-induced currents. Time-resolved cathodoluminescence measurements find short carrier liftetimes consistent with reduced polarization fields. Our results show nanostructuring to be a promising route to deep-UV-emitting LEDs, achievable using commercially compatible methods. |
