Open AccessCore-shell p-i-n GaN nanowire LEDs by N-polar selective area growth
Author(s) -
Matthew D. Brubaker,
Kristen L. Genter,
Joel C. Weber,
Bryan T. Spann,
Alexana Roshko,
Paul T. Blanchard,
Todd E. Harvey,
Kristine A. Bertness
Publication year - 2018
Publication title -
pubmed central
Language(s) - English
Resource type - Conference proceedings
SCImago Journal Rank - 0.192
H-Index - 176
pISSN - 0277-786X
DOI - 10.1117/12.2322832
Subject(s) - light emitting diode , materials science , optoelectronics , electroluminescence , nanowire , wide bandgap semiconductor , biasing , leakage (economics) , layer (electronics) , nanotechnology , voltage , economics , macroeconomics , physics , quantum mechanics
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.