Negatively charged excitons in semimagnetic CdSe/ZnSe/ZnMnSe quantum dots

Journal Article · Wed Aug 15 00:00:00 EDT 2007 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S1063776107080109· OSTI ID:21075727

Chernenko, A V; Chekhovich, E A; Dorozhkin, P S; Kulakovskii, V D ^[1]; Ivanov, S V; Toropov, A A ^[2]

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1. Russian Academy of Sciences, Institute of Solid State Physics (Russian Federation)
2. Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)

Low-temperature (T = 1.6 K) photoluminescence (PL) of individual CdSe/ZnSe/ZnMnSe quantum dots (QDs) with different magnitudes of the sp-d exchange interaction between the magnetic impurity ions and charge carriers has been studied in a magnetic field up to 12 T applied in the Faraday and Voigt geometry. The magnitude of the interaction was controlled by changing the fraction ({eta}{sub e,h}) of the squared wave function of charge carriers in the semimagnetic barrier by means of variation of the nonmagnetic (ZnSe) layer thickness. It is established that the sp-d exchange interaction leads to a change in the sign of the effective hole g factor even for {eta}{sub e,h} {approx} 5%, while further increase in the interaction magnitude is accompanied by a rapid growth in the magnitude of spin splitting for both electrons and holes. The quantum yield of PL exhibits a significant decrease due to nonradiative Auger recombination with the excitation of Mn ions only for {eta}{sub e,h} {approx} 12%, while the rate of the holes spin relaxation starts growing only for still higher {eta}{sub e,h} values. In a strong magnetic field perpendicular to the sample plane, the alignment of Mn spins leads to suppression of the Auger recombination only in the excited spin state. For a small rate of the hole spin relaxation, this leads to a rather unusual result: the emission from an excited trion state predominates in strong magnetic fields.

• OSTI ID: 21075727
• Journal Information: Journal of Experimental and Theoretical Physics, Vol. 105, Issue 2; Other Information: DOI: 10.1134/S1063776107080109; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CADMIUM SELENIDES
CHARGE CARRIERS
ELECTRONS
EXCHANGE INTERACTIONS
EXCITATION
EXCITONS
HOLES
LANDE FACTOR
MAGNETIC FIELDS
MANGANESE IONS
MANGANESE SELENIDES
PHOTOLUMINESCENCE
QUANTUM DOTS
RECOMBINATION
SPIN
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0000-0013 K
WAVE FUNCTIONS
ZINC SELENIDES