Abstract
A nonpolar a -plane GaN-based light emitting structure was patterned by self-assembled SiO2 nanosphere lithography and subsequent inductively coupled plasma (ICP) etch to define an array of nanopillar light emitters. The photoluminescence (PL) intensity was enhanced by ∼110% after the anisotropic ICP etch, compared with an unprocessed sample, which is attributed to a reduction in wave-guiding effects in the thin film. Additionally, the anisotropic ICP etch caused minimal wavelength shift in the dominant 3.34 eV near-bandedge radiative transition. A subsequent photoelectrochemical (PEC) etch process of the a -plane GaN nanopillars preferentially etched the underlying n -type layers, leaving a wider p -type cap. The n -type layers wet-etched by recession of the N-polar (000-1) plane (perpendicular to the a -plane growth axis) via formation of the distinctive pyramid-shaped facets. The PL intensity was enhanced by ∼168% after ICP and PEC etching although the peak emission occurred at a lower energy. The combination of nanosphere lithography and ICP was highly effective in improving the light extraction efficiency in a -plane nonpolar GaN-based light emitting diodes.
Original language | English |
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Article number | 021004 |
Journal | Journal of Vacuum Science and Technology B:Nanotechnology and Microelectronics |
Volume | 29 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2011 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Instrumentation
- Process Chemistry and Technology
- Surfaces, Coatings and Films
- Electrical and Electronic Engineering
- Materials Chemistry