Core-Shell p-i-n GaN Nanowire LEDs by N-polar Selective Area Growth

Published

September 11, 2018

Author(s)

Matthew D. Brubaker, Kristen L. Genter, Bryan T. Spann, Alexana Roshko, Paul T. Blanchard, Todd E. Harvey, Kristine A. Bertness

Abstract

GaN nanowire LEDs with radial p-i-n junctions were grown by molecular beam epitaxy using N- polar selective area growth on Si(111) substrates. The N-polar selective area growth process facilitated the growth of isolated and high-aspect-ratio n-type NW cores that were not subject to self-shadowing effects during the subsequent growth of a conformal low-temperature Mg:GaN shell. LED devices were fabricated from single-NW and multiple-NW arrays in their as-grown configuration by contacting the n-type core through an underlying conductive GaN layer and the p-type NW shell via a metallization layer. The NW LEDs exhibited rectifying I-V characteristics with a sharp turn-on voltage near the GaN bandgap and low reverse bias leakage current. Under forward bias, the NW LEDs produced electroluminescence with a peak emission wavelength near 380 nm and exhibited a small spectral blueshift with increasing current injection, both of which are consistent with electron recombination in the p-type shell layer through donor-acceptor- pair recombination. These core-shell NW devices demonstrate N-polar selective area growth as an effective technique for producing on-chip nanoscale light sources.

Citation

Proceedings of SPIE

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Keywords

gallium nitride, N-polar, nanowires, light-emitting diodes, core-shell, selective area growth

Citation

Brubaker, M. , Genter, K. , Spann, B. , Roshko, A. , Blanchard, P. , Harvey, T. and Bertness, K. (2018), Core-Shell p-i-n GaN Nanowire LEDs by N-polar Selective Area Growth, Proceedings of SPIE, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=926383 (Accessed October 9, 2025)