Quantum confinement effects in Si/Ge heterostructures with spatially ordered arrays of self-assembled quantum dots

Agafonov, Oleksiy B.; Dais, Christian; Grützmacher, Detlev; Haug, Rolf J.
May 2010
Applied Physics Letters;5/31/2010, Vol. 96 Issue 22, p222107
Academic Journal
Magnetotunneling spectroscopy was employed to probe the confinement in vertical Si/Ge double-barrier resonant tunneling diodes with regularly distributed Ge quantum dots. Their current-voltage characteristics reveal a steplike behavior in the vicinity of zero bias, indicating resonant tunneling of heavy-holes via three-dimensionally confined unoccupied hole states in Ge quantum dots. Assuming parabolic confinement, we extract the strength of the confinement potential of quantum dots.


Related Articles

  • Spin Dynamics of a Single Mn Ion in a CdTe/(Cd, Mg, Zn)Te Quantum Dot. Goryca, Mateusz; Kossacki, Piotr; Golnik, Andrzej; Kazimierczuk, Tomasz; Wojnar, Piotr; Nawrocki, Michał // AIP Conference Proceedings;1/4/2010, Vol. 1199 Issue 1, p453 

    The spin dynamics of a single Mn ion confined in a CdTe/(Cd, Mg, Zn)Te quantum dot is determined by measurements of photon correlation of photoluminescence. The characteristic time of spin flip is a few nanoseconds and strongly depends on the excitation power.

  • Strong coupling in a quantum dot micropillar system under electrical current injection. Kistner, C.; Morgener, K.; Reitzenstein, S.; Schneider, C.; Höfling, S.; Worschech, L.; Forchel, A.; Yao, P.; Hughes, S. // Applied Physics Letters;5/31/2010, Vol. 96 Issue 22, p221102 

    Integrating In0.3Ga0.7As quantum dots (QDs) featuring a high oscillator strength into a high quality electrically contacted micropillar cavity enabled us to realize strong coupling under electrical carrier injection. In the micropillar cavity with a quality factor of 10 000 and a diameter of 1.9...

  • Q-factor and density of optical modes in pyramidal and cone-shaped GaAs microcavities. Karl, M.; Beck, T.; Li, S.; Kalt, H.; Hetterich, M. // Applied Physics Letters;6/9/2008, Vol. 92 Issue 23, p231105 

    GaAs pyramids on top of GaAs/AlAs distributed Bragg reflectors (DBRs) are studied as candidates for microcavities with low mode volume. Photoluminescence spectra of single pyramids with embedded quantum dots show cavity modes with quality (Q-) factors of up to 700. Furthermore, to assess the...

  • Frequency dependent electrical characteristics of PbS quantum dots. S. Chowdhury; A. Hussain; G. Ahmed; A. Choudhury // European Physical Journal - Applied Physics;May2008, Vol. 42 Issue 2, p113 

    PbS quantum dots (bare and silica coated) have been synthesized in PVA matrix with average size 10?nm and 9?nm. The capacitance-voltage (C-V) and current ?voltage (I-V) response of both bare and coated quantum dots have been recorded in different frequency range (Hz?MHz). Both the samples show...

  • Interlevel transitions and two-photon processes in Ge/Si quantum dot photocurrent. Finkman, E.; Shuall, N.; Vardi, A.; Le Thanh, V.; Schacham, S. E. // Journal of Applied Physics;May2008, Vol. 103 Issue 9, p093114 

    Photocurrent spectra due to interlevel transitions of holes in Ge/Si quantum dots show several peaks in the range of 60–300 meV, which superlinearly increase with bias, indicating release of carriers by tunneling. The relative peak intensity drastically changes with applied voltage, its...

  • Synthesis of quantum dots via microreaction: structure optimization for microreactor system. Yang, Hongwei; Luan, Weiling; Cheng, Rui; Chu, Haijian; Tu, Shan-tung // Journal of Nanoparticle Research;Aug2011, Vol. 13 Issue 8, p3335 

    Microreactor systems existed as a powerful tool for the continuous synthesis of quantum dots. However, the lack of structure optimization for the discrete units led to empirical determination of the length scale, and the properties of the formed products varied in different cases. In this...

  • Localized formation of InAs quantum dots on shallow-patterned GaAs(100). Wang, Zh. M.; Lee, J. H.; Liang, B. L.; Black, W. T.; Kunets, Vas. P.; Mazur, Yu. I.; Salamo, G. J. // Applied Physics Letters;6/5/2006, Vol. 88 Issue 23, p233102 

    Selective formation of InAs quantum dots on the sidewalls of mesa strips along both [01-1] and [011] directions of a GaAs(100) surface is demonstrated. This result is in sharp contrast to observations on traditionally deep-patterned substrates, where quantum dots are formed on top mesas and at...

  • Differential reflection spectroscopy of a single quantum dot strongly coupled to a photonic crystal cavity. Kim, Erik D.; Majumdar, Arka; Kim, Hyochul; Petroff, Pierre; Vucˇkovic, Jelena // Applied Physics Letters;8/2/2010, Vol. 97 Issue 5, p053111 

    We demonstrate the use of periodically modulated Coulomb shifts in quantum dot (QD) transition energies to obtain differential reflection spectra of a photonic crystal nanocavity containing strongly coupled dots. Measured spectra isolate the change in the empty cavity optical reflectivity...

  • Quantum Electrodynamics with Semiconductor Quantum Dots Coupled to Anderson-localized Random Cavities. Sapienza, Luca; Thyrrestrup, Henri; Stobbe, So\ren; Garcia, Pedro David; Smolka, Stephan; Lodahl, Peter // AIP Conference Proceedings;12/22/2011, Vol. 1399 Issue 1, p999 

    We demonstrate that the spontaneous emission decay rate of semiconductor quantum dots can be strongly modified by the coupling to disorder-induced Anderson-localized photonic modes. We experimentally measure, by means of time-resolved photoluminescence spectroscopy, the enhancement of the...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics