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Publication Citation: Large-Area GaN n-p Core-Shell Arrays Fabricated Using Top-Down Etching and Selective Epitaxial Overgrowth

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Author(s): Abhishek Motayed; Sergiy Krylyuk; Dipak Paramanik; Matt N. King; Jong Yoon Ha; Albert Davydov; John E. Bonevich;
Title: Large-Area GaN n-p Core-Shell Arrays Fabricated Using Top-Down Etching and Selective Epitaxial Overgrowth
Published: December 10, 2012
Abstract: We present large-area, vertically-aligned GaN core-shell structures on silicon substrates. The GaN cores were formed by inductively coupled plasma etching of patterned n-type GaN epitaxial layer. The Mg-doped GaN shells were formed using selective overgrowth by halide vapor phase epitaxy. The diameter of the cores ranged from 250 nm to 10 um with varying pitch. The p-type shells formed truncated hexagonal pyramids with prismatic [1101] side-facets. Room-temperature photoluminescence, and Raman scattering measurements indicated strain-relaxation in the etched cores and shells. Cross-sectional transmission electron microscopy revealed dislocation bending by 90 degrees in the shells, which led to their reduction in the overgrown shells.
Citation: Journal of Applied Physics
Volume: 101
Issue: 24
Keywords: Core-shell; GaN, nanostructures; p-n junction; top-down
Research Areas: Thin-Films