High-efficiency InGaN-based light-emitting diodes with nanoporous GaN:Mg structure
- Department of Materials Engineering, National Chung Hsing University, Taichung, Taiwan (China)
In this research nanoporous structures on p-type GaN:Mg and n-type GaN:Si surfaces were fabricated through a photoelectrochemical (PEC) oxidation and an oxide-removing process. The photoluminescence (PL) intensities of GaN and InGaN/GaN multi-quantum-well (MQW) structures were enhanced by forming this nanoporous structure to increase light extraction efficiency. The PL emission peaks of an MQW active layer have a blueshift phenomenon from 465.5 nm (standard) to 456.0 nm (nanoporous) measured at 300 K which was caused by partially releasing the compressive strain from the top GaN:Mg layers. The internal quantum efficiency could be increased by a partial strain release that induces a lower piezoelectric field in the active layer. The thermal activation energy of a nanoporous structure (85 meV) is higher than the standard one (33 meV) from a temperature dependent PL measurement. The internal quantum efficiency and light extraction efficiency of an InGaN/GaN MQW active layer are significantly enhanced by this nanoporous GaN:Mg surface, and this PEC treated nanoporous structure is suitable for high-power lighting applications.
- OSTI ID:
- 20778693
- Journal Information:
- Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 8 Vol. 88; ISSN APPLAB; ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ACTIVATION ENERGY
GALLIUM NITRIDES
INDIUM NITRIDES
LAYERS
LIGHT EMITTING DIODES
MAGNESIUM
MEV RANGE 10-100
OXIDATION
OXIDES
PHOTOLUMINESCENCE
PIEZOELECTRICITY
POROUS MATERIALS
QUANTUM EFFICIENCY
QUANTUM WELLS
SEMICONDUCTOR MATERIALS
SILICON
SPECTRAL SHIFT
STRAINS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K