Article ID Journal Published Year Pages File Type
1532237 Materials Science and Engineering: B 2006 4 Pages PDF
Abstract

The effects of the GaN epilayers and LED structures grown by metalorganic chemical vapor deposition on 1° off c-plane sapphire substrate were studied. Although the 1° off-axis GaN sample has slightly rough surface morphology, it has narrower full-width at half-maximum (FWHM) of X-ray asymmetrical reflection (10–12), higher mobility, lower compensating acceptor concentration and lower etching pits densities (EPD) than the on-axis GaN sample. And it also has lower etching pits densities (EPD). To reduce the threading dislocations in GaN films grown on vicinal substrates is attributed. A very weak yellow luminescence is observed in photoluminescence (PL) spectra of 1° off-axis GaN sample. Finally, comparing to LED structures grown on on-axis c-plane sapphire substrates, the LED structures grown on 1° off substrate show a blue shift of PL wavelength and 2.6 times stronger in PL intensity. The electroluminescence (EL) intensity of 1° LED sample rises faster in small amount of driving current region.

Related Topics
Physical Sciences and Engineering Materials Science Electronic, Optical and Magnetic Materials
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