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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Temperature dependence of the photoluminescence of self-assembled InAs/GaAs quantum dots studied in high magnetic fields.
AU - Nuytten, Thomas
AU - Hayne, Manus
AU - Henini, Mohamed
AU - Moshchalkov, Victor V.
N1 - The final, definitive version of this article has been published in the Microelectronics Journal, 40 (3), 2009, © ELSEVIER.
PY - 2009/3
Y1 - 2009/3
N2 - We have investigated the photoluminescence (PL) of self-assembled InAs/GaAs quantum dots (QDs) in high magnetic fields of up to 50 T and as a function of temperature. Our data clearly indicate that two different mechanisms are at work. At low temperatures (T < 80 K), the zero-field PL is increasingly dominated by lower energy dots. High-field measurements however demonstrate that these dots are larger in size only in the growth direction. At temperatures above 100 K, a strong decrease of the PL peak energy shift with field is observed, while the zero-field PL is characterized by a redshift according to the changes in the bandgap. We discuss these contradictory observations in terms of a phenomenon that we call field-assisted enhancement of the QD barrier potential. Since this effect is much stronger for small high-energy QDs, the latter progressively dominate the PL emission when temperature and magnetic field are increased.
AB - We have investigated the photoluminescence (PL) of self-assembled InAs/GaAs quantum dots (QDs) in high magnetic fields of up to 50 T and as a function of temperature. Our data clearly indicate that two different mechanisms are at work. At low temperatures (T < 80 K), the zero-field PL is increasingly dominated by lower energy dots. High-field measurements however demonstrate that these dots are larger in size only in the growth direction. At temperatures above 100 K, a strong decrease of the PL peak energy shift with field is observed, while the zero-field PL is characterized by a redshift according to the changes in the bandgap. We discuss these contradictory observations in terms of a phenomenon that we call field-assisted enhancement of the QD barrier potential. Since this effect is much stronger for small high-energy QDs, the latter progressively dominate the PL emission when temperature and magnetic field are increased.
KW - Photoluminescence
KW - Semiconductor quantum dots
KW - III-V Semiconductors
U2 - 10.1016/j.mejo.2008.06.059
DO - 10.1016/j.mejo.2008.06.059
M3 - Journal article
VL - 40
SP - 486
EP - 488
JO - Microelectronics Journal
JF - Microelectronics Journal
IS - 3
ER -