Formation and properties of InGaN QDs: Influence of substrates
| العنوان: | Formation and properties of InGaN QDs: Influence of substrates |
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| المؤلفون: | J. C. Walrath, A. S. Chang, Pallab Bhattacharya, Thomas Frost, J. Occena, Christian Greenhill, Rachel Goldman, Arnab Hazari |
| المصدر: | Applied Physics Letters. 114:062106 |
| بيانات النشر: | AIP Publishing, 2019. |
| سنة النشر: | 2019 |
| مصطلحات موضوعية: | 010302 applied physics, Materials science, Physics and Astronomy (miscellaneous), business.industry, Superlattice, Scanning tunneling spectroscopy, Nucleation, Wide-bandgap semiconductor, 02 engineering and technology, Substrate (electronics), 021001 nanoscience & nanotechnology, 01 natural sciences, law.invention, Quantum dot, law, 0103 physical sciences, Sapphire, Optoelectronics, Scanning tunneling microscope, 0210 nano-technology, business |
| الوصف: | We examine the formation and properties of InGaN quantum dots (QDs) on free-standing GaN and GaN/sapphire templates, with and without buried InGaN/GaN QD superlattices (SLs). We use scanning tunneling microscopy (STM) and scanning tunneling spectroscopy to image the QDs and measure their electronic states. As the number of layers preceding the QDs increases (i.e., increasing substrate complexity), the total QD density increases. For free-standing GaN, STM reveals a mono-modal QD-size-distribution, consistent with a limited density of substrate threading dislocations serving as heterogeneous nucleation sites. For GaN/sapphire templates, STM reveals a bimodal QD-size-distribution, presumably due to the nucleation of additional ultra-small InN-rich QDs near threading dislocations. For multi-period QD SLs on GaN/sapphire templates, an ultra-high density of QDs, with a mono-modal size distribution is apparent, suggesting that QD nucleation is enhanced by preferential nucleation at strain energy minima directly above buried QDs. We discuss the relative influences of strain fields associated with threading dislocations and buried QD SLs on the formation of InGaN QDs and their effective bandgaps. |
| تدمد: | 1077-3118 0003-6951 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::3e2b14dcf0ed94dde5c4bf41ad8d5dd8 https://doi.org/10.1063/1.5053856 |
| رقم الأكسشن: | edsair.doi...........3e2b14dcf0ed94dde5c4bf41ad8d5dd8 |
| قاعدة البيانات: | OpenAIRE |
Find this article in full text from Scitation. | تدمد: | 10773118 00036951 |
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