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



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


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.
Proceedings of SPIE


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


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], (Accessed May 29, 2024)


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Created September 10, 2018, Updated July 6, 2020