Regensburg 2010 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 36: Poster: Nanoparticles and Composite Materials

CPP 36.21: Poster

Wednesday, March 24, 2010, 17:30–19:00, Poster B2

Auger release of a deeply trapped carrier in a quantum dot — •Thomas Hartmann¹, Peter Reineker¹, and Vladimir I. Yudson² — ¹Abteilung Theoretische Physik, Universität Ulm, 89069 Ulm — ²Institute for Spectroscopy, Russian Academy of Sciences, Troitsk, Moscow region, 142190, Russia

For a quantum dot (QD) we have studied the transiton between the dark and the bright states on the basis of an Auger-induced release process of an electron deeply trapped in a QD shell. The importance of this release process mechanism in connection with the dark state termination has not been noticed before. The considered release mechanism originates from an elcectron-hole pair which is created by light irradiation and whose energy - after recombination - is transferred to the trapped electron via a Förster-like mechansism ∼ 1/r₀⁶, where r₀ is the distance between the QD center and the trap in the shell. The spatial distribution of deep traps over the QD results in a distribution of "off-times". For a homogeneous spatial distribution of traps and a Förster-like dependence of the trapping probability, the distribution of the "off-times" follows a power law ∼ 1/t_off^3/2 with the exponent 3/2 observed experimentally in many QDs.