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Structural and optical properties of position-retrievable low-density GaAs droplet epitaxial quantum dots for application to single photon sources with plasmonic optical coupling.

Lee EH, Song JD, Han IK, Chang SK, Langer F, Höfling S, Forchel A, Kamp M, Kim JS - Nanoscale Res Lett (2015)

Bottom Line: The position of a single GaAs quantum dot (QD), which is optically active, grown by low-density droplet epitaxy (DE) (approximately 4 QDs/μm(2)), was directly observed on the surface of a 45-nm-thick Al0.3Ga0.7As capping layer.The thin thickness of AlGaAs capping layer is useful for single photon sources with plasmonic optical coupling.A micro-photoluminescence for GaAs DE QDs has shown exciton/biexciton behavior in the range of 1.654 to 1.657 eV.

View Article: PubMed Central - PubMed

Affiliation: Center for Opto-Electronic Convergence Systems, Korea Institute of Science and Technology, Seoul, 136-791 South Korea ; Institute of Physics and Applied Physics, Yonsei University, Seoul, 120-749 South Korea.

ABSTRACT
The position of a single GaAs quantum dot (QD), which is optically active, grown by low-density droplet epitaxy (DE) (approximately 4 QDs/μm(2)), was directly observed on the surface of a 45-nm-thick Al0.3Ga0.7As capping layer. The thin thickness of AlGaAs capping layer is useful for single photon sources with plasmonic optical coupling. A micro-photoluminescence for GaAs DE QDs has shown exciton/biexciton behavior in the range of 1.654 to 1.657 eV. The direct observation of positions of low-density GaAs DE QDs would be advantageous for mass fabrication of devices that use a single QD, such as single photon sources.

No MeSH data available.


Related in: MedlinePlus

Macro-PL and SEM image. (a) Macro-PL (log scale) of low-density GaAs DE QDs with 22- and 45-nm cap at low temperature (12 K). The PL intensity was normalized with PL peak intensity of GaAs-related peak band around 830 nm. (b) SEM image (x300,000) of low-density GaAs DE QDs with 45-nm AlGaAs capping layer. The inset of Figure 3b is magnified by four for one QD.
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Fig3: Macro-PL and SEM image. (a) Macro-PL (log scale) of low-density GaAs DE QDs with 22- and 45-nm cap at low temperature (12 K). The PL intensity was normalized with PL peak intensity of GaAs-related peak band around 830 nm. (b) SEM image (x300,000) of low-density GaAs DE QDs with 45-nm AlGaAs capping layer. The inset of Figure 3b is magnified by four for one QD.

Mentions: For low-density GaAs DE QDs with 22- and 45-nm capping, a macro-PL at a low temperature (approximately 12 K) was measured, to verify an emission of low-density GaAs DE QDs, as shown in Figure 3a. Low-density GaAs DE QDs with a 45-nm-thick capping layer showed an emission at approximately 779 nm. However, 22-nm-capped GaAs DE QDs had no emission peak of QDs. An emission at approximately 779 nm for low-density GaAs DE QDs with a 45-nm capping matches the macro-PL result of 773-nm emission in Figure 1c. The PL bands around 660 and 830 nm shown in Figures 1c and 3a are attributed to Al0.3Ga0.7As and GaAs, respectively. The larger intensity of the PL band near 660 nm is found with the thicker AlGaAs capping layer in Figure 3a.Figure 3


Structural and optical properties of position-retrievable low-density GaAs droplet epitaxial quantum dots for application to single photon sources with plasmonic optical coupling.

Lee EH, Song JD, Han IK, Chang SK, Langer F, Höfling S, Forchel A, Kamp M, Kim JS - Nanoscale Res Lett (2015)

Macro-PL and SEM image. (a) Macro-PL (log scale) of low-density GaAs DE QDs with 22- and 45-nm cap at low temperature (12 K). The PL intensity was normalized with PL peak intensity of GaAs-related peak band around 830 nm. (b) SEM image (x300,000) of low-density GaAs DE QDs with 45-nm AlGaAs capping layer. The inset of Figure 3b is magnified by four for one QD.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Fig3: Macro-PL and SEM image. (a) Macro-PL (log scale) of low-density GaAs DE QDs with 22- and 45-nm cap at low temperature (12 K). The PL intensity was normalized with PL peak intensity of GaAs-related peak band around 830 nm. (b) SEM image (x300,000) of low-density GaAs DE QDs with 45-nm AlGaAs capping layer. The inset of Figure 3b is magnified by four for one QD.
Mentions: For low-density GaAs DE QDs with 22- and 45-nm capping, a macro-PL at a low temperature (approximately 12 K) was measured, to verify an emission of low-density GaAs DE QDs, as shown in Figure 3a. Low-density GaAs DE QDs with a 45-nm-thick capping layer showed an emission at approximately 779 nm. However, 22-nm-capped GaAs DE QDs had no emission peak of QDs. An emission at approximately 779 nm for low-density GaAs DE QDs with a 45-nm capping matches the macro-PL result of 773-nm emission in Figure 1c. The PL bands around 660 and 830 nm shown in Figures 1c and 3a are attributed to Al0.3Ga0.7As and GaAs, respectively. The larger intensity of the PL band near 660 nm is found with the thicker AlGaAs capping layer in Figure 3a.Figure 3

Bottom Line: The position of a single GaAs quantum dot (QD), which is optically active, grown by low-density droplet epitaxy (DE) (approximately 4 QDs/μm(2)), was directly observed on the surface of a 45-nm-thick Al0.3Ga0.7As capping layer.The thin thickness of AlGaAs capping layer is useful for single photon sources with plasmonic optical coupling.A micro-photoluminescence for GaAs DE QDs has shown exciton/biexciton behavior in the range of 1.654 to 1.657 eV.

View Article: PubMed Central - PubMed

Affiliation: Center for Opto-Electronic Convergence Systems, Korea Institute of Science and Technology, Seoul, 136-791 South Korea ; Institute of Physics and Applied Physics, Yonsei University, Seoul, 120-749 South Korea.

ABSTRACT
The position of a single GaAs quantum dot (QD), which is optically active, grown by low-density droplet epitaxy (DE) (approximately 4 QDs/μm(2)), was directly observed on the surface of a 45-nm-thick Al0.3Ga0.7As capping layer. The thin thickness of AlGaAs capping layer is useful for single photon sources with plasmonic optical coupling. A micro-photoluminescence for GaAs DE QDs has shown exciton/biexciton behavior in the range of 1.654 to 1.657 eV. The direct observation of positions of low-density GaAs DE QDs would be advantageous for mass fabrication of devices that use a single QD, such as single photon sources.

No MeSH data available.


Related in: MedlinePlus