Structural optimization of lattice-matched Sc0.14Al0.86N/GaN superlattices for photonic applications
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arXiv
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| Autores principales: | , , , , |
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| Formato: | Preprint |
| Publicado: |
2025
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| _version_ | 1866916840155906048 |
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| author | Kumar, Rajendra Gopakumar, Govardan Abdin, Zain Ul Manfra, Michael J. Malis, Oana |
| author_facet | Kumar, Rajendra Gopakumar, Govardan Abdin, Zain Ul Manfra, Michael J. Malis, Oana |
| contents | ScxAl1-xN is an emerging III-nitride material known for its high piezoelectric coefficient and ferroelectric properties. Integration of wide-bandgap ScxAl1-xN with GaN is particularly attractive for quantum photonic devices. Achieving low defect complex multilayers incorporating ScxAl1-xN, though, requires precise lattice-matching and carefully optimized growth parameters. This study systematically investigates the molecular-beam epitaxy of short-period ScxAl1-xN/GaN superlattices with total thicknesses of up to 600 nm on GaN templates. X-ray diffraction reciprocal space mapping confirmed lattice-matching at x = 0.14 Sc composition regardless of the thickness of GaN interlayers, as evidenced by symmetric superlattice satellites aligned in-plane with the underlying substrate peak. Superlattices with Sc compositions deviating from this lattice-matching condition exhibited strain-induced defects ranging from crack formation to partial relaxation. Scanning transmission electron microscopy (STEM) investigation of the ScxAl1-xN/GaN interfaces identified temperature-dependent intermixing as a major factor in setting the nitride composition variation and implicitly band structure profile along the growth direction. Energy-dispersive X-ray spectroscopy also revealed that Sc incorporation exhibits delays relative to Al at both onset and termination. Optimal growth conditions were observed at approximately 600°C and 550°C for superlattices with thick GaN layers (6 nm), and ultra-thin GaN layers (< 2 nm), respectively. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2507_08951 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Structural optimization of lattice-matched Sc0.14Al0.86N/GaN superlattices for photonic applications Kumar, Rajendra Gopakumar, Govardan Abdin, Zain Ul Manfra, Michael J. Malis, Oana Materials Science ScxAl1-xN is an emerging III-nitride material known for its high piezoelectric coefficient and ferroelectric properties. Integration of wide-bandgap ScxAl1-xN with GaN is particularly attractive for quantum photonic devices. Achieving low defect complex multilayers incorporating ScxAl1-xN, though, requires precise lattice-matching and carefully optimized growth parameters. This study systematically investigates the molecular-beam epitaxy of short-period ScxAl1-xN/GaN superlattices with total thicknesses of up to 600 nm on GaN templates. X-ray diffraction reciprocal space mapping confirmed lattice-matching at x = 0.14 Sc composition regardless of the thickness of GaN interlayers, as evidenced by symmetric superlattice satellites aligned in-plane with the underlying substrate peak. Superlattices with Sc compositions deviating from this lattice-matching condition exhibited strain-induced defects ranging from crack formation to partial relaxation. Scanning transmission electron microscopy (STEM) investigation of the ScxAl1-xN/GaN interfaces identified temperature-dependent intermixing as a major factor in setting the nitride composition variation and implicitly band structure profile along the growth direction. Energy-dispersive X-ray spectroscopy also revealed that Sc incorporation exhibits delays relative to Al at both onset and termination. Optimal growth conditions were observed at approximately 600°C and 550°C for superlattices with thick GaN layers (6 nm), and ultra-thin GaN layers (< 2 nm), respectively. |
| title | Structural optimization of lattice-matched Sc0.14Al0.86N/GaN superlattices for photonic applications |
| topic | Materials Science |
| url | https://arxiv.org/abs/2507.08951 |