Low dislocation GaN via defect-filtering, self-assembled SiO2-sphere layers [electronic resource].
- Washington, D.C. : United States. Dept. of Energy, 2009.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- 23 pages : digital, PDF file
- Additional Creators:
- Sandia National Laboratories, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- The III-nitride (AlGaInN) materials system forms the foundation for white solid-state lighting, the adoption of which could significantly reduce U.S. energy needs. While the growth of GaN-based devices relies on heteroepitaxy on foreign substrates, the heteroepitaxial layers possess a high density of dislocations due to poor lattice and thermal expansion match. These high dislocation densities have been correlated with reduced internal quantum efficiency and lifetimes for GaN-based LEDs. Here, we demonstrate an inexpensive method for dislocation reduction in GaN grown on sapphire and silicon substrates. This technique, which requires no lithographic patterning, GaN is selectively grown through self-assembled layers of silica microspheres which act to filter out dislocations. Using this method, the threading dislocation density for GaN on sapphire was reduced from 3.3 x 10⁹ cm⁻² to 4.0 x 10⁷ cm⁻², and from the 10¹° cm⁻² range to ≈6.0 x 10⁷ cm⁻² for GaN on Si(111). This large reduction in dislocation density is attributed to a dislocation blocking and bending by the unique interface between GaN and silica microspheres.
- Report Numbers:
- E 1.99:sand2009-6153
- Other Subject(s):
- Published through SciTech Connect.
Wang, George T.; Li, Qiming.
- Funding Information:
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