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Updated: Jun 13, 2026

Correlative Light- and Electron Microscopy Using Quantum Dot Nanoparticles
Published on: August 7, 2016
Hole-induced electron transport through core-shell quantum dots: a direct measurement of the electron-hole
Ingmar Swart1, Zhixiang Sun, Daniël Vanmaekelbergh
1Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, University of Utrecht, Utrecht, The Netherlands. ingmar.swart@physik.uni-regensburg.de
Abstract:
Quantum dots (QDs) have promising optoelectronic properties. Colloidal QD heterostructures, systems in which two semiconductors are incorporated in a single colloid, may show novel and potentially useful transport phenomena. Here, we report on the physical mechanisms of charge transport through PbSe-CdSe core-shell QDs measured with cryogenic scanning tunneling spectroscopy. Compared to single-component QDs, an additional hole-induced electron tunneling channel is found. Electron tunneling with and without a hole occurs at different bias, allowing the determination of the electron-hole interaction energy (80 meV). This energy is sufficiently large to allow for a transport regime at room temperature in which electrons tunnel into the dot only if a hole is present, an ideal situation for controlled single-photon emission.
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