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Selective area epitaxy of ultra-high density InGaN quantum dots by diblock copolymer lithography.

Liu G, Zhao H, Zhang J, Park JH, Mawst LJ, Tansu N - Nanoscale Res Lett (2011)

Bottom Line: The cylindrical-shaped nanopatterns were created on SiNx layers deposited on a GaN template, which provided the nanopatterning for the epitaxy of ultra-high density QD with uniform size and distribution.The InGaN/GaN QDs with density up to 8 × 1010 cm-2 are realized, which represents ultra-high dot density for highly uniform and well-controlled, nitride-based QDs, with QD diameter of approximately 22-25 nm.The photoluminescence (PL) studies indicated the importance of NH3 annealing and GaN spacer layer growth for improving the PL intensity of the SiNx-treated GaN surface, to achieve high optical-quality QDs applicable for photonics devices.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center for Optical Technologies, Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA. gul308@lehigh.edu.

ABSTRACT
Highly uniform InGaN-based quantum dots (QDs) grown on a nanopatterned dielectric layer defined by self-assembled diblock copolymer were performed by metal-organic chemical vapor deposition. The cylindrical-shaped nanopatterns were created on SiNx layers deposited on a GaN template, which provided the nanopatterning for the epitaxy of ultra-high density QD with uniform size and distribution. Scanning electron microscopy and atomic force microscopy measurements were conducted to investigate the QDs morphology. The InGaN/GaN QDs with density up to 8 × 1010 cm-2 are realized, which represents ultra-high dot density for highly uniform and well-controlled, nitride-based QDs, with QD diameter of approximately 22-25 nm. The photoluminescence (PL) studies indicated the importance of NH3 annealing and GaN spacer layer growth for improving the PL intensity of the SiNx-treated GaN surface, to achieve high optical-quality QDs applicable for photonics devices.

No MeSH data available.


SEM images of SAE-grown InGaN/GaN QDs after removal of SiNx layer for both samples investigated: (a) sample A; (b) sample B.
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Figure 5: SEM images of SAE-grown InGaN/GaN QDs after removal of SiNx layer for both samples investigated: (a) sample A; (b) sample B.

Mentions: The SEM images of the samples A and B after the removal of SiNx layer by HF wet etching were shown in Figure 5a,b, respectively. The SEM measurements indicate that the QDs on both the samples were comparable in both the size and distribution with QDs before the elimination of the SiNx layer. The QD diameters were estimated to be about 22 and 25 nm on the samples A and B, respectively. The QD densities for the samples A and B were measured as 7 × 10 and 8 × 1010 cm-2, respectively, which happen to be among the highest QD density reported for InGaN material systems.


Selective area epitaxy of ultra-high density InGaN quantum dots by diblock copolymer lithography.

Liu G, Zhao H, Zhang J, Park JH, Mawst LJ, Tansu N - Nanoscale Res Lett (2011)

SEM images of SAE-grown InGaN/GaN QDs after removal of SiNx layer for both samples investigated: (a) sample A; (b) sample B.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211431&req=5

Figure 5: SEM images of SAE-grown InGaN/GaN QDs after removal of SiNx layer for both samples investigated: (a) sample A; (b) sample B.
Mentions: The SEM images of the samples A and B after the removal of SiNx layer by HF wet etching were shown in Figure 5a,b, respectively. The SEM measurements indicate that the QDs on both the samples were comparable in both the size and distribution with QDs before the elimination of the SiNx layer. The QD diameters were estimated to be about 22 and 25 nm on the samples A and B, respectively. The QD densities for the samples A and B were measured as 7 × 10 and 8 × 1010 cm-2, respectively, which happen to be among the highest QD density reported for InGaN material systems.

Bottom Line: The cylindrical-shaped nanopatterns were created on SiNx layers deposited on a GaN template, which provided the nanopatterning for the epitaxy of ultra-high density QD with uniform size and distribution.The InGaN/GaN QDs with density up to 8 × 1010 cm-2 are realized, which represents ultra-high dot density for highly uniform and well-controlled, nitride-based QDs, with QD diameter of approximately 22-25 nm.The photoluminescence (PL) studies indicated the importance of NH3 annealing and GaN spacer layer growth for improving the PL intensity of the SiNx-treated GaN surface, to achieve high optical-quality QDs applicable for photonics devices.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center for Optical Technologies, Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA. gul308@lehigh.edu.

ABSTRACT
Highly uniform InGaN-based quantum dots (QDs) grown on a nanopatterned dielectric layer defined by self-assembled diblock copolymer were performed by metal-organic chemical vapor deposition. The cylindrical-shaped nanopatterns were created on SiNx layers deposited on a GaN template, which provided the nanopatterning for the epitaxy of ultra-high density QD with uniform size and distribution. Scanning electron microscopy and atomic force microscopy measurements were conducted to investigate the QDs morphology. The InGaN/GaN QDs with density up to 8 × 1010 cm-2 are realized, which represents ultra-high dot density for highly uniform and well-controlled, nitride-based QDs, with QD diameter of approximately 22-25 nm. The photoluminescence (PL) studies indicated the importance of NH3 annealing and GaN spacer layer growth for improving the PL intensity of the SiNx-treated GaN surface, to achieve high optical-quality QDs applicable for photonics devices.

No MeSH data available.