Novel Approach for Energy Spectrum Probing in Semiconducting Quantum Dots
M. Zdrojeka, M. W─ůsika, M.J. Esplandiub and A. Bachtoldb
aFaculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland
bCIN2(CSIC-ICN), Campus UAB, E-08193 Bellaterra, Spain
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A new technique has been used to probe the electronic properties of quantum dots. Here we discuss the case of semiconducting CdSe dots. This technique allows us to fill (or empty) semiconducting quantum dot with many electrons. The detection scheme is based on an original approach where the investigated particle is attached to only one electrode, a carbon nanotube. The conductance of the nanotube is measured as a function of a gate voltage (Vg), which allows the detection of individual electrons transferred onto the quantum dot. For certain range of Vg we noticed no electron transfer which is attributed to the energy gap of the CdSe quantum dot. Our study shows that single-electron detection with carbon nanotube transistor represents a new strategy to study the separation between the electronic discrete energy levels of the semiconducting quantum dot.
DOI: 10.12693/APhysPolA.122.321
PACS numbers: 73.22.Dj, 73.23.Hk, 73.63.Kv