Optical characterization of individual quantum dots
2012 (English)In: Physica. B, Condensed matter, ISSN 0921-4526, Vol. 407, no 10, 1472-1475 p.Article in journal (Refereed) Published
Optical characterization of single quantum dots (QDs) by means of micro-photoluminescence (mu PL) will be reviewed. Both QDs formed in the Stranski-Krastanov mode as well as dots in the apex of pyramidal structures will be presented. For InGaAs/GaAs dots, several excitonic features with different charge states will be demonstrated. By varying the magnitude of an external electric or magnetic field and/or the temperature, it has been demonstrated that the transportation of carriers is affected and accordingly the charge state of a single QD can be tuned. In addition, we have shown that the charge state of the QD can be controlled also by pure optical means, i.e. by altering the photo excitation conditions. Based on the experience of the developed InAs/GaAs QD system, similar methods have been applied on the InGaN/GaN QD system. less thanbrgreater than less thanbrgreater thanThe coupling of LO phonons to the QD emission is experimentally examined for both charged and neutral excitons in single InGaAs/GaAs QDs in the apex of pyramidal structures. It is shown that the positively charged exciton exhibits a significantly weaker LO phonon coupling in the mu PL spectra than the neutral and negatively charged species, a fact, which is in consistency with model simulations performed.
Place, publisher, year, edition, pages
Elsevier , 2012. Vol. 407, no 10, 1472-1475 p.
Quantum dots, Pyramid, Exciton, Photoluminescence
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-77523DOI: 10.1016/j.physb.2011.09.064ISI: 000303149600005OAI: oai:DiVA.org:liu-77523DiVA: diva2:528610
Funding Agencies|Swedish Research Council (VR)||Swedish Foundation for Strategic Research (SSF)||Nano-N consortium||Science Foundation Ireland|05/IN.1/I25|Knut and Alice Wallenberg Foundation||INSPIRE||2012-05-282012-05-222015-01-23