Semi-polar {1   0 1} blue and green InGaN/GaN light-emitting diodes on micro-stripe patterned Si (1 0 0). (5th November 2015)

• Record Type: Journal Article
• Authors: Reuters, B; Strate, J; Wille, A; Marx, M; Lükens, G; Heuken, L; Heuken, M; Kalisch, H; Vescan, A
• Is Part Of: Journal of physics. Volume 48:Number 48(2015)
• Publication Date: 2015-11-05
• Subjects: light-emitting diodes -- blue LED -- green LED -- semi-polar -- quantum wells -- quantum-confined stark effect -- metalorganic chemical vapor deposition; Physics -- Periodicals; 530
• DOI: 10.1088/0022-3727/48/48/485103
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: A novel III-nitride-based light emitting diode (LED) fabrication process which is based on selective-area epitaxial growth on Si {1 1 1} facets etched into Si (1 0 0) substrates is presented. A micro-stripe pattern is formed with semi-polar {1 0 1} crystallographic planes of GaN evolving from an epitaxial lateral overgrowth (ELOG)-like process. The {1 0 1} planes of GaN serve as a template for the growth of semi-polar blue and green LED structures with InGaN/GaN multiple quantum wells (MQW). A complete fabrication chain encompassing substrate etching, metalorganic vapor phase epitaxy (MOVPE), characterization, LED processing and device manufacture has been developed. The semi-polar LED stacks are of high crystalline quality, which is manifested by homogeneous InGaN layers in the {1 0 1} MQW structure and smooth {1 0 1} LED surface planes. Although threading dislocations intersect with the semi-polar {1 0 1} MQW, V-shaped defects typically observed in polar c -plane MQW structures are not detected. The blue and green semi-polar LED show only a weak polarization-related wavelength shift at large current densities consistent with the lower built-in electric fields in the semi-polar MQW. At low current densities, the green LED exhibit a strong wavelength shift due to In clustering effects. The blue LED reveal a stable emission color, which indicates a homogeneous In distribution in the wells.