Abstract
Self-assembled GaAs/AlGaAs quantum dot pairs (QDPs) are grown by molecular beam epitaxy using high temperature droplet epitaxy technique. A typical QDP consists of dual-size quantum dots as observed based on atomic force microscopy image. The average height of quantum dot is 5.7 nm for the large quantum dots and 4.6 nm for the small ones. The average peak-to-peak distance of the two dots is about 75 nm. The optical properties of GaAs QDPs are studied by measuring excitation power-dependent and temperature-dependent photoluminescence. Unique photoluminescence properties have been observed from both excitation power-dependent and temperature-dependent measurements. Excitation power-dependent as well as temperature-dependent PL measurements have suggested lateral exciton transfer in the QDPs.
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Abbreviations
- QD:
-
Quantum dot
- QDM:
-
Quantum dot molecule
- PL:
-
Photoluminescence
- S–K:
-
Stranski–Krastanow
- QDP:
-
Quantum dot pair
- AFM:
-
Atomic force microscopy
References
AbuWaar ZY, Wang ZM, Lee JH, Salamo GJ (2006) Observation of Ga droplet formation on (311)A and (511)A GaAs surfaces. Nanotechnology 17:4037–4040
Bouzaïene L, Sfaxi L, Baira M, Maaref H, Bru-Chevallier C (2010) Power density and temperature dependent multi-excited states in InAs/GaAs quantum dots. J Nanopart Res: 1–6. doi:10.1007/s11051-010-0024-1
Dai YT, Fan JC, Chen YF, Lin RM, Lee SC, Lin HH (1997) Temperature dependence of photoluminescence spectra in InAs/GaAs quantum dot superlattices with large thicknesses. J Appl Phys 82:4489
Hanke M, Schmidbauer M, Grigoriev D, Schäfer P, Köhler R, Metzger TH, Wang ZM, Mazur YI, Salamo GJ (2006) Zero-strain GaAs quantum dot molecules as investigated by x-ray diffuse scattering. Appl Phys Lett 89:053116
Heitz R, Mukhametzhanov I, Madhukar A, Hoffmann A, Bimberg D (1999) Temperature dependent optical properties of self-organized InAs/GaAs quantum dots. J Electron Mater 28:520–527
Ledentsov NN, Shchukin VA, Grundmann M, Kirstaedter N, Böhrer J, Schmidt O, Bimberg D, Ustinov VM, Egorov AY, Zhukov AE, Kop’ev PS, Zaitsev SV, Gordeev NY, Alferov ZI, Borovkov AI, Kosogov AO, Ruvimov SS, Werner P, Gösele U, Heydenreich J (1996) Direct formation of vertically coupled quantum dots in Stranski-Krastanow growth. Phys Rev B 54:8743
Lee JH, Wang ZM, Strom NW, Mazur YI, Salamo GJ (2006) InGaAs quantum dot molecules around self-assembled GaAs nanomound templates. Appl Phys Lett 89:202101
Lee JH, Wang ZM, Kim NY, Salamo GJ (2009) Size and density control of in droplets at near room temperatures. Nanotechnology 20:285602
Li S, Xia J (1997) Intraband optical absorption in semiconductor coupled quantum dots. Phys Rev B 55:15434–15437
Li S, Xia J (2007) Electronic structures of N quantum dot molecule. Appl Phys Lett 91:092119
Li S, Xia J, Yuan Z, Xu Z, Ge W, Wang X, Wang Y, Wang J, Chang L (1996) Effective-mass theory for InAs/GaAs strained coupled quantum dots. Phys Rev B 54:11575–11581
Li S, Abliz A, Yang F, Niu Z, Feng S, Xia J, Hirose K (2003) Electron transport through coupled quantum dots. J Appl Phys 94:5402
Liang B, Wang Z, Wang X, Lee J, Mazur YI, Shih C, Salamo GJ (2008) Energy transfer within ultralow density twin InAs quantum dots grown by droplet epitaxy. ACS Nano 2(11):2219–2224
Livermore C, Crouch CH, Westervelt RM, Campman KL, Gossard AC (1996) The Coulomb blockade in coupled quantum dots. Science 274:1332–1335
Mano T, Kuroda T, Kuroda K, Sakoda K (2009) Self-assembly of quantum dots and rings by droplet epitaxy and their optical properties. J Nanophotonics 3:031605
Polimeni A, Patanè A, Henini M, Eaves L, Main P (1999) Temperature dependence of the optical properties of InAs/AlyGa1-yAs self-organized quantum dots. Phys Rev B 59:5064–5068
Pomraenke R, Lienau C, Mazur YI, Wang ZM, Liang B, Tarasov GG, Salamo GJ (2008) Near-field optical spectroscopy of GaAs/AlyGa1-yAs quantum dot pairs grown by high-temperature droplet epitaxy. Phys Rev B 77:075314
Sanguinetti S, Mano T, Oshima M, Tateno T, Wakaki M, Koguchi N (2002) Temperature dependence of the photoluminescence of InGaAs/GaAs quantum dot structures without wetting layer. Appl Phys Lett 81:3067
Schramm A, Tukiainen A, Aho A, Pessa M (2009) Comparing morphology studies of GaAs quantum dots grown by droplet epitaxy on GaInP and GaAs. J Cryst Growth 311:2317–2320
Somaschini C, Bietti S, Koguchi N, Sanguinetti S (2009) Fabrication of multiple concentric nanoring structures. Nano Lett 9:3419–3424
Stinaff EA, Scheibner M, Bracker AS, Ponomarev IV, Korenev VL, Ware ME, MDoty F, Reinecke TL, Gammon D (2006) Optical signatures of coupled quantum dots. Science 311:636–639
Wang ZM, Holmes K, Mazur YI, Ramsey KA, Salamo GJ (2006) Self-organization of quantum-dot pairs by high-temperature droplet epitaxy. Nanoscale Res Lett 1:57–61
Wang ZM, Mazur YI, Sablon KA, Mishima TD, Johnson MB, Salamo GJ (2008) Unusual role of the substrate in droplet-induced GaAs/AlGaAs quantum-dot pairs. Phys Status Solidi 2:281–283
Wu J, Shao D, Dorogan VG, Li AZ, Li S, Decuir EA, Manasreh MO, Wang ZM, Mazur YI, Salamo GJ (2010) Intersublevel infrared photodetector with strain-free GaAs quantum dot pairs grown by high-temperature droplet epitaxy. Nano Lett 10:1512–1516
Yamagiwa M, Mano T, Kuroda T, Tateno T, Sakoda K, Kido G, Koguchi N, Minami F (2006) Self-assembly of laterally aligned GaAs quantum dot pairs. Appl Phys Lett 89:113115
Yang CC, Li S (2008) Size, dimensionality, and constituent stoichiometry dependence of bandgap energies in semiconductor quantum dots and wires. J Phys Chem C 112:2851–2856
Acknowledgments
This work is supported by the MRSEC Program of NSF Grant No. (DMR-0520550) and the Arkansas Biosciences Institute.
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Wu, J., Wang, Z.M., Dorogan, V.G. et al. Insight into optical properties of strain-free quantum dot pairs. J Nanopart Res 13, 947–952 (2011). https://doi.org/10.1007/s11051-010-0219-5
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DOI: https://doi.org/10.1007/s11051-010-0219-5