GaN-based light emitting diodes (LEDs) grown on 4-in. Si (111)
substrate by metal–organic chemical vapor deposition have been systematically
characterized. The significantly smooth surface of the sample has been confirmed
by an atomic force microscope. In X-ray diffraction measurement, two kinds of
fringe peaks were observed, which are believed to originate from the
strained-layer superlattice (SLS) and multiple quantum wells. Moreover, from
cross-sectional scanning electron microscope images of the sample, it is found
that the interfaces of SLS are smooth. The 100-pair AlN/GaN SLS can be employed
to modulate the strain between the GaN layer and substrate, resulting in the
improvement of GaN crystalline quality. The full width at half maximum of
ω-scan of the GaN (0002) diffraction is around 630ʺ. In addition, the
device properties have been investigated in detail, and the maximum light output
power can reach 2.02 mW with a high saturation injection current of
320 mA.
Keywords
- GaN;
- Silicon substrate;
- Light-emitting diodes;
- Metal–organic chemical vapor deposition;
- Light output power
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