Mechanisms for intraband energy relaxation in semiconductor quantum dots: The role of electron-hole interactions

被引:224
作者
Klimov, VI
Mikhailovsky, AA
McBranch, DW
Leatherdale, CA
Bawendi, MG
机构
[1] Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA
[2] MIT, Dept Chem, Cambridge, MA 02139 USA
[3] MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA
关键词
D O I
10.1103/PhysRevB.61.R13349
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
To evaluate the role of nonphonon energy relaxation mechanisms in quantum dots and in particular the role of electron-hole (e-h) interactions, we have studied femtosecond carrier dynamics in CdSe colloidal nanoparticles in which the e-h separation (coupling) is controlled using different types of surface ligands. In dots capped with hole accepting molecules, the e-h coupling is strongly reduced after the hole is transferred to a capping group. By re-exciting an electron within the conduction band at different stages of hole transfer and monitoring its relaxation back into the ground state, we observe a more than tenfold increase in the electron relaxation time (from 250 fs to 3 ps) after the completion of the hole transfer to the capping molecule. This strongly indicates that electron relaxation in quantum dots is dominated not by phonon emission but by the e-h energy transfer.
引用
收藏
页码:13349 / 13352
页数:4
相关论文
共 22 条
  • [1] Semiconductor clusters, nanocrystals, and quantum dots
    Alivisatos, AP
    [J]. SCIENCE, 1996, 271 (5251) : 933 - 937
  • [2] INTRINSIC MECHANISM FOR THE POOR LUMINESCENCE PROPERTIES OF QUANTUM-BOX SYSTEMS
    BENISTY, H
    SOTOMAYORTORRES, CM
    WEISBUCH, C
    [J]. PHYSICAL REVIEW B, 1991, 44 (19) : 10945 - 10948
  • [3] ELECTRON RELAXATION IN QUANTUM DOTS BY MEANS OF AUGER PROCESSES
    BOCKELMANN, U
    EGELER, T
    [J]. PHYSICAL REVIEW B, 1992, 46 (23): : 15574 - 15577
  • [4] Electron shuttling across the interface of CdSe nanoparticles monitored by femtosecond laser spectroscopy
    Burda, C
    Green, TC
    Link, S
    El-Sayed, MA
    [J]. JOURNAL OF PHYSICAL CHEMISTRY B, 1999, 103 (11): : 1783 - 1788
  • [5] HOT-ELECTRON RELAXATION IN SEMICONDUCTOR QUANTUM WIRES - BULK-LO-PHONON EMISSION
    CAMPOS, VB
    DASSARMA, S
    [J]. PHYSICAL REVIEW B, 1992, 45 (07): : 3898 - 3901
  • [6] Conwell E. M., 1967, HIGH FIELD TRANSPORT
  • [7] EFROS AL, 1995, SOLID STATE COMMUN, V93, P281, DOI 10.1016/0038-1098(94)00780-2
  • [8] ABSORPTION AND INTENSITY-DEPENDENT PHOTOLUMINESCENCE MEASUREMENTS ON CDSE QUANTUM DOTS - ASSIGNMENT OF THE 1ST ELECTRONIC-TRANSITIONS
    EKIMOV, AI
    HACHE, F
    SCHANNEKLEIN, MC
    RICARD, D
    FLYTZANIS, C
    KUDRYAVTSEV, IA
    YAZEVA, TV
    RODINA, AV
    EFROS, AL
    [J]. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS, 1993, 10 (01) : 100 - 107
  • [9] Intraband relaxation in CdSe quantum dots
    Guyot-Sionnest, P
    Shim, M
    Matranga, C
    Hines, M
    [J]. PHYSICAL REVIEW B, 1999, 60 (04) : R2181 - R2184
  • [10] Synthesis and characterization of strongly luminescing ZnS-Capped CdSe nanocrystals
    Hines, MA
    Guyot-Sionnest, P
    [J]. JOURNAL OF PHYSICAL CHEMISTRY, 1996, 100 (02) : 468 - 471