Effect of Rapid Thermal Annealing: Red and Blue Shift in Photoluminescence of GaNAs Grown by RF Plasma-Assisted Molecular Beam Epitaxy
NANYANG TECHNOLOGICAL INST (SINGAPORE)
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Rapid thermal annealing RTA of 1000A GaNAs films grown on 100 oriented GaAs substrate by radio frequency RF plasma assisted solid-source molecular beam epitaxy was studied by low-temperature photoluminescence PL and high-resolution x-ray diffraction HRXRD. Samples with nitrogen content of 1.3 and 2.2 have shown an overall blueshift in energy of 67.7 meV and an intermediate redshift of 42.2 meV in the PL spectra when subjected to RTA at 529-850 deg C for 10 min. It is also shown that the sample which is annealed at temperature range of 700-750 deg C, has the highest photoluminescence efficiency 1.7-2.1 times increase in integrated PL intensity as compared to the as-grown sample. Reciprocal space mapping of the as-grown GaNAs samples obtained by using triple-crystal HRXRD shows the presence of interstitially incorporated of N atoms with no lattice relaxation in the direction parallel to the growth surface. These results have significant implication on the growth and post-growth treatment of nitride compound semiconductor materials for high performance optoelectronics devices.
- Solid State Physics