Optical Spectroscopy on Magnetically Doped Semiconductor Nanoparticles

  • Lars Schneider
  • Gerd Bacher
Part of the NanoScience and Technology book series (NANO)


Semiconductor nanoparticles doped with magnetic ions represent an exciting class of materials with unique optical, electronic, and magnetic properties and potential applications in the field of spintronics. A key feature required is the exchange interaction between magnetic ions and charge carriers, which finally controls the magneto-optical response of these materials. In this contribution, some recent advances for two classes of magnetically doped nanoparticles, namely, ZnO doped with Cr and Co, respectively, and CdSe doped with Mn, are summarized. We found that chromium is incorporated as Cr\(^{3+}\) in ZnO. With increasing Cr concentration, the quantum efficiency is being reduced while the magnetic properties observed can be attributed to a phase separation between ZnO and ZnCr\(_{2}\)O\(_{4}\). In contrast, cobalt apparently exists in the Co\(^{2+}\) configuration in the nanocrystals as demonstrated via optical spectroscopy. No enhanced magneto-optical properties have been obtained for both classes of magnetically doped ZnO nanoparticles. This is completely different in case of Mn-doped CdSe nanocrystals. A giant Zeeman effect is found as a consequence of a pronounced spd exchange interaction. The strong 3D carrier confinement finally results in a significantly enhanced exchange field leading to the observation of optically induced magnetism up to room temperature.


Exchange Field CdSe Nanoparticles CdSe Nanocrystals Recombination Lifetime Bright Exciton 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The authors are indebted to Wei Jin, Ruzica Djenadic and Markus Winterer for preparing the Cr\(^{3+}\)- and Co\(^{2+}\)-doped ZnO nanoparticles and performing XRD and XANES measurements and Mehmet Acet for SQUID investigations of ZnO:Cr\(^{3+}\) nanoparticles. The preparation of excellent CdSe:Mn\(^{2+}\) nanocrystals by Remi Beaulac, Paul I Archer, and Daniel R. Gamelin, and the very fruitful collaboration in that field is gratefully acknowledged. We thank Rachel Fainblat-Padua for a critical reading of the manuscript and the German Research Foundation for financial support within the SFB 445—Nanoparticles from the gas phase.


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© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  1. 1.Electronic Materials and Nanodevices, Faculty of Engineering and CENIDEUniversity of Duisburg-EssenDuisburgGermany

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