TITLE

Origin of ultraviolet photoluminescence in ZnO quantum dots: Confined excitons versus surface-bound impurity exciton complexes

AUTHOR(S)
Fonoberov, Vladimir A.; Balandin, Alexander A.
PUB. DATE
December 2004
SOURCE
Applied Physics Letters;12/13/2004, Vol. 85 Issue 24, p5971
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
We have theoretically investigated the origin of ultraviolet photoluminescence (PL) in ZnO quantum dots with diameters from 2 to 6 nm. Two possible sources of ultraviolet PL have been considered: excitons confined in the quantum dot and excitons bound to an ionized impurity located at the quantum-dot surface. It is found that depending on the fabrication method and surface passivation technique, the ultraviolet PL of ZnO quantum dots can be attributed to either confined excitons or surface-bound ionized acceptor-exciton complexes. The exciton radiative lifetime is shown to be very sensitive to the exciton localization and can be used as a tool to discriminate between these two sources of PL.
ACCESSION #
15331849

 

Related Articles

  • Photoluminescence of localized excitons in InGan quantum dots. Usov, S.; Tsatsul’nikov, A.; Lundin, V.; Sakharov, A.; Zavarin, E.; Ledentsov, N. // Semiconductors;Feb2008, Vol. 42 Issue 2, p188 

    Photoluminescence spectra of samples with ultrathin InGaN layers embedded in AlGaN and GaN matrices are studied experimentally in the temperature range of 80 to 300 K. It is shown that the temperature dependences can be understood in the context of Eliseev’s model and that, in the active...

  • Splitting of excitons and biexcitons in coupled InAs quantum dot molecules. Xu, Xiulai; Williams, D. A.; Cleaver, J. R. A. // Applied Physics Letters;1/3/2005, Vol. 86 Issue 1, p012103 

    Coupling in laterally coupled InAs quantum dot molecules has been observed by conventional microscopic photoluminescence spectroscopy. At low excitation intensity, splitting of exciton emission is observed, and this is ascribed to recombination of bonding and antibonding states when two quantum...

  • Electrical charging of a single quantum dot by a spin polarized electron. Ghali, M.; Kümmell, T.; Wenisch, J.; Brunner, K.; Bacher, G. // Applied Physics Letters;8/18/2008, Vol. 93 Issue 7, p073107 

    Voltage controlled electrical charging of a single InAs quantum dot by a spin polarized electron from a ZnMnSe spin aligner is presented, and the spin information is read out optically. We demonstrate that the characteristic single quantum dot photoluminescence polarization pattern of the...

  • Self-assembled ZnO quantum dots with tunable optical properties. Lu, J. G.; Ye, Z. Z.; Zhang, Y. Z.; Liang, Q. L.; Fujita, Sz.; Wang, Z. L. // Applied Physics Letters;7/10/2006, Vol. 89 Issue 2, p023122 

    Self-assembled ZnO quantum dots (QDs) were achieved by a vapor phase transport process. ZnO nanodots were naturally formed on solid substrates in the Volmer-Weber growth mode. Size control of nanodots could be readily realized by varying the growth time. The as-prepared ZnO QDs are of high...

  • Strongly confined excitons in self-assembled InGaAs quantum dot clusters produced by a hybrid growth method. Creasey, Megan; Li, Xiaoqin; Lee, J. H.; Wang, Zh. M.; Salamo, G. J. // Journal of Applied Physics;Jun2010, Vol. 107 Issue 10, p104302 

    We investigate the optical properties of newly developed InGaAs quantum dot clusters (QDCs). The QDCs are produced using a hybrid growth method that combines droplet homoepitaxy and Stranski–Krastanov growth modes. We focus on a particular geometry, where six individual quantum dots (QDs)...

  • Comment on “Giant exciton-light coupling in ZnO quantum dots” [Appl. Phys. Lett. 81, 748 (2002)]. Fonoberov, Vladimir A.; Balandin, Alexander A. // Applied Physics Letters;5/30/2005, Vol. 86 Issue 22, p226101 

    Comments on B. Gil and A.V. Kavokin's article about the calculation of the radiative lifetime in ZnO quantum dots. Reported value for the radiative lifetime of bulk ZnO, measured using the time-resolved photoluminescence spectroscopy; Error in the examination which affected the final result;...

  • Optical Properties of Tetrahedral Quantum Dot Quantum Wells. Fonoberov, V. A.; Pokatilov, E. P.; Fomin, V. M.; Devreese, J. T. // AIP Conference Proceedings;2005, Vol. 772 Issue 1, p673 

    Taking into account the tetrahedral shape of a quantum dot quantum well (QDQW) when describing excitonic states, phonon modes and the exciton-phonon interaction in the structure, we obtain a quantitative interpretation of the photoluminescence (PL) spectrum of a single CdS/HgS/CdS QDQW within a...

  • Modes of Excitation in Two-Dimensional Quantum Dots. Huang, G. M.; Liu, Y. M.; Bao, C. G. // Few-Body Systems;Sep2005, Vol. 37 Issue 3, p121 

    The electronic structures of low-lying excited states of a polarized quantum dot with 6 electrons has been studied. The Hamiltonian has been diagonalized to obtain the eigenstates. All results are extracted from a detailed analysis of wave functions. Six modes were found that lead to distinct...

  • The coherent time evolution of two coupled quantum dots in a two-mode cavity. Yuan, X.; Zhu, K.; Li, W. // European Physical Journal D -- Atoms, Molecules, Clusters & Opti;Dec2004, Vol. 31 Issue 3, p499 

    For two coupled identical quantum dots in a two-mode cavity, we determine the conditions of two-photon and single-photon resonance. It is shown that the exciton-phonon interaction reduces the Rabi frequencies of each model and the F�rster interaction between double quantum dots even at...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

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

Try another library?
Sign out of this library

Other Topics