Skip to main content Accessibility help
Hostname: page-component-79b67bcb76-x7pwn Total loading time: 0.327 Render date: 2021-05-14T18:09:32.129Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "metricsAbstractViews": false, "figures": false, "newCiteModal": false, "newCitedByModal": true, "newEcommerce": true }

Fabrication of ultralow-density quantum dots by droplet etching epitaxy

Published online by Cambridge University Press:  26 October 2017

Jiang Wu
Department of Electronic and Electrical Engineering, University College London, London WC1E 7JE, U.K.
Zhiming M. Wang
Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, People’s Republic of China
Xinlei Li
MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, People’s Republic of China
Yuriy I. Mazur
Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States of America
Gregory J. Salamo
Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States of America
Get access


Isolated single quantum dots (QDs) enable the investigation of quantum-optics phenomena for the application of quantum information technologies. In this work, ultralow-density InAs QDs are grown by combining droplet etching epitaxy and the conventional epitaxy growth mode. An extreme low density of QDs (∼106 cm−2) is realized by creating low-density self-assembled nanoholes with the high temperature droplet etching epitaxy technique and then nanohole-filling. The preferred nucleation of QDs in nanoholes has been explained by a theoretical model. Atomic force microscopy and the photoluminescence technique are used to investigate the morphological and optical properties of the QD samples. By varying In coverages, the size of InAs QDs can be controlled. Moreover, with a thin GaAs cap layer, the position of QDs remains visible on the sample surface. Such a low density and surface signature of QDs make this growth method promising for single QD investigation and single dot device fabrication.

Invited Articles
Copyright © Materials Research Society 2017 

Access options

Get access to the full version of this content by using one of the access options below.


Contributing Editor: Artur Braun


Semonin, O.E., Luther, J.M., Choi, S., Chen, H., Gao, J., Nozik, A.J., and Beard, M.C.: Peak external photocurrent quantum efficiency exceeding 100% via MEG in a quantum dot solar cell. Science 334, 1530 (2011).CrossRefGoogle Scholar
Lee, S.J., Ku, Z., Barve, A., Montoya, J., Jang, W., Brueck, S.R.J., Sundaram, M., Reisinger, A., Krishna, S., and Noh, S.K.: A monolithically integrated plasmonic infrared quantum dot camera. Nat. Commun. 2, 286 (2011).CrossRefGoogle ScholarPubMed
Zhang, J., Huo, Y., Rastelli, A., Zopf, M., Höfer, B., Chen, Y., Ding, F., and Schmidt, O.G.: Single photons on-demand from light-hole excitons in strain-engineered quantum dots. Nano Lett. 15, 422 (2014).CrossRefGoogle ScholarPubMed
Wu, J., Yu, P., Susha, A.S., Sablon, K.A., Chen, H., Zhou, Z., Li, H., Ji, H., Niu, X., and Govorov, A.O.: Broadband efficiency enhancement in quantum dot solar cells coupled with multispiked plasmonic nanostars. Nano Energy 13, 827 (2015).CrossRefGoogle Scholar
Tatebayashi, J., Kako, S., Ho, J., Ota, Y., Iwamoto, S., and Arakawa, Y.: Room-temperature lasing in a single nanowire with quantum dots. Nat. Photonics 9, 501 (2015).CrossRefGoogle Scholar
Wu, J., Shao, D., Dorogan, V.G., Li, A.Z., Li, S., Decuir, E.A., Manasreh, M.O., Wang, Z.M., Mazur, Y.I., and Salamo, G.J.: Intersublevel infrared photodetector with strain-free GaAs quantum dot pairs grown by high-temperature droplet epitaxy. Nano Lett. 10, 15121516 (2010).CrossRefGoogle ScholarPubMed
Chang, W., Chen, W., Chang, H., Hsieh, T., Chyi, J., and Hsu, T.: Efficient single-photon sources based on low-density quantum dots in photonic-crystal nanocavities. Phys. Rev. Lett. 96, 117401 (2006).CrossRefGoogle ScholarPubMed
Kamiya, I., Tanaka, I., and Sakaki, H.: Control of size and density of self-assembled InAs dots on (001) GaAs and the dot size dependent capping process. J. Cryst. Growth 201–202, 1146 (1999).CrossRefGoogle Scholar
Kamiya, I., Tanaka, I., Ohtsuki, O., and Sakaki, H.: Density and size control of self-assembled InAs quantum dots: Preparation of very low-density dots by post-annealing. Phys. E 13, 1172 (2002).CrossRefGoogle Scholar
Ohmori, M., Kawazu, T., Torii, K., Takahashi, T., and Sakaki, H.: Formation of ultra-low density (≤104 cm−2) self-organized InAs quantum dots on GaAs by a modified molecular beam epitaxy method. Appl. Phys. Express 1, 061202 (2008).CrossRefGoogle Scholar
Silva, M.J.d., Quivy, A.A., González-Borrero, P.P., Marega, E., and Leite, J.R.: Atomic-force microscopy study of self-assembled InAs quantum dots along their complete evolution cycle. J. Cryst. Growth 241, 19 (2002).CrossRefGoogle Scholar
Sun, J., Jin, P., and Wang, Z.: Extremely low density InAs quantum dots realized in situ on (100) GaAs. Nanotechnology 15, 17631766 (2004).CrossRefGoogle Scholar
Dubrovskii, V., Cirlin, G., Brunkov, P., Perimetti, U., and Akopyan, N.: Ultra-low density InAs quantum dots. Semiconductors 47, 1324 (2013).CrossRefGoogle Scholar
Jin, P., Ye, X.L., and Wang, Z.G.: Growth of low-density InAs/GaAs quantum dots on a substrate with an intentional temperature gradient by molecular beam epitaxy. Nanotechnology 16, 27752778 (2005).CrossRefGoogle Scholar
Huang, S., Niu, Z., Ni, H., Xiong, Y., Zhan, F., Fang, Z., and Xia, J.: Fabrication of ultra-low density and long-wavelength emission InAs quantum dots. J. Cryst. Growth 301–302, 751 (2007).CrossRefGoogle Scholar
Trevisi, G., Seravalli, L., Frigeri, P., and Franchi, S.: Low density InAs/(In)GaAs quantum dots emitting at long wavelengths. Nanotechnology 20, 415607 (2009).CrossRefGoogle Scholar
Schneider, C., Strauss, M., Sunner, T., Huggenberger, A., Wiener, D., Reitzenstein, S., Kamp, M., Hofling, S., and Forchel, A.: Lithographic alignment to site-controlled quantum dots for device integration. Appl. Phys. Lett. 92, 183101 (2008).CrossRefGoogle Scholar
Schneider, C., Huggenberger, A., Sunner, T., Heindel, T., Strauss, M., Gopfert, S., Weinmann, P., Reitzenstein, S., Worschech, L., Kamp, M., Hofling, S., and Forchel, A.: Single site-controlled in(Ga)As/GaAs quantum dots: Growth, properties and device integration. Nanotechnology 20, 434012 (2009).CrossRefGoogle ScholarPubMed
Toujyou, T. and Tsukamoto, S.: Temperature-dependent site control of InAs/GaAs (001) quantum dots using a scanning tunneling microscopy tip during growth. Nanoscale Res. Lett. 5, 1930 (2010).CrossRefGoogle ScholarPubMed
Liang, B.L., Wang, Z.M., Lee, J.H., Sablon, K., Mazur, Y.I., and Salamo, G.J.: Low density InAs quantum dots grown on GaAs nanoholes. Appl. Phys. Lett. 89, 043113 (2006).CrossRefGoogle Scholar
Alonso-González, P., Martín-Sánchez, J., González, Y., Alén, B., Fuster, D., and González, L.: Formation of lateral low density In(Ga)As quantum dot pairs in GaAs nanoholes. Cryst. Growth Des. 9, 2525 (2009).CrossRefGoogle Scholar
Wu, J. and Wang, Z.M.: Droplet epitaxy for advanced optoelectronic materials and devices. J. Phys. D: Appl. Phys. 47, 173001 (2014).CrossRefGoogle Scholar
Huo, Y., Witek, B., Kumar, S., Cardenas, J., Zhang, J., Akopian, N., Singh, R., Zallo, E., Grifone, R., and Kriegner, D.: A light-hole exciton in a quantum dot. Nat. Phys. 10, 46 (2014).CrossRefGoogle Scholar
Pfeiffer, M., Lindfors, K., Zhang, H., Fenk, B., Phillipp, F., Atkinson, P., Rastelli, A., Schmidt, O.G., Giessen, H., and Lippitz, M.: Eleven nanometer alignment precision of a plasmonic nanoantenna with a self-assembled GaAs quantum dot. Nano Lett. 14, 197 (2014).CrossRefGoogle ScholarPubMed
Wei, Q., Lian, J., Lu, W., and Wang, L.: Highly ordered Ga nanodroplets on a GaAs surface formed by a focused ion beam. Phys. Rev. Lett. 100, 076103 (2008).CrossRefGoogle ScholarPubMed
Wang, Z.M., Holmes, K., Shultz, J.L., and Salamo, G.J.: Self-assembly of GaAs holed nanostructures by droplet epitaxy. Phys. Status Solidi A 202, R85 (2005).CrossRefGoogle Scholar
Li, A.Z., Wang, Z.M., Wu, J., Xie, Y., Sablon, K.A., and Salamo, G.J.: Evolution of holed nanostructures on GaAs (001). Cryst. Growth Des. 9, 29412943 (2009).CrossRefGoogle Scholar
Heyn, C., Stemmann, A., and Hansen, W.: Nanohole formation on AlGaAs surfaces by local droplet etching with gallium. J. Cryst. Growth 311, 18391842 (2009).CrossRefGoogle Scholar
Wang, Z.M., Liang, B.L., Sablon, K.A., and Salamo, G.J.: Nanoholes fabricated by self-assembled gallium nanodrill on GaAs(100). Appl. Phys. Lett. 90, 113120 (2007).CrossRefGoogle Scholar
Heyn, C., Stemmann, A., Schramm, A., Welsch, H., Hansen, W., and Nemcsics, Á.: Regimes of GaAs quantum dot self-assembly by droplet epitaxy. Phys. Rev. B 76, 075317 (2007).CrossRefGoogle Scholar
Heyn, C., Bartsch, T., Sanguinetti, S., Jesson, D., and Hansen, W.: Dynamics of mass transport during nanohole drilling by local droplet etching. Nanoscale Res. Lett. 10, 67 (2015).CrossRefGoogle ScholarPubMed
Heyn, C.: Kinetic model of local droplet etching. Phys. Rev. B 83, 165302 (2011).CrossRefGoogle Scholar
Wang, Z.M., Liang, B., Sablon, K.A., Lee, J., Mazur, Y.I., Strom, N.W., and Salamo, G.J.: Self-organization of InAs quantum-dot clusters directed by droplet homoepitaxy. Small 3, 235 (2007).CrossRefGoogle ScholarPubMed
Li, X., Wu, J., Wang, Z.M., Liang, B., Lee, J., Kim, E., and Salamo, G.J.: Origin of nanohole formation by etching based on droplet epitaxy. Nanoscale 6, 2675 (2014).CrossRefGoogle ScholarPubMed
Li, X.: Selective formation mechanisms of quantum dots on patterned substrates. Phys. Chem. Chem. Phys. 15, 5238 (2013).CrossRefGoogle ScholarPubMed
Huo, Y.H., Křápek, V., Rastelli, A., and Schmidt, O.G.: Volume dependence of excitonic fine structure splitting in geometrically similar quantum dots. Phys. Rev. B 90, 041304(R) (2014).CrossRefGoogle Scholar
Schmidbauer, M., Wang, Z.M., Mazur, Y.I., Lytvyn, P., Salamo, G., Grigoriev, D., Schäfer, P., Köhler, R., and Hanke, M.: Initial stages of chain formation in a single layer of (In,Ga)As quantum dots grown on GaAs(100). Appl. Phys. Lett. 91, 093110 (2007).CrossRefGoogle Scholar
Supplementary material: File

Wu et al. supplementary material

Figure S1

Download Wu et al. supplementary material(File)
File 2 MB

Send article to Kindle

To send this article to your Kindle, first ensure is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

Note you can select to send to either the or variations. ‘’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Fabrication of ultralow-density quantum dots by droplet etching epitaxy
Available formats

Send article to Dropbox

To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

Fabrication of ultralow-density quantum dots by droplet etching epitaxy
Available formats

Send article to Google Drive

To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

Fabrication of ultralow-density quantum dots by droplet etching epitaxy
Available formats

Reply to: Submit a response

Your details

Conflicting interests

Do you have any conflicting interests? *