Enhanced carrier multiplication in engineered quasi-type-II quantum dots

Claudiu M. Cirloganu, Lazaro A. Padilha, Qianglu Lin, Nikolay S. Makarov, Kirill A. Velizhanin, Hongmei Luo, Istvan Robel, Jeffrey M. Pietryga, Victor I Klimov

Research output: Contribution to journalArticle

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Abstract

One process limiting the performance of solar cells is rapid cooling (thermalization) of hot carriers generated by higher-energy solar photons. In principle, the thermalization losses can be reduced by converting the kinetic energy of energetic carriers into additional electron-hole pairs via carrier multiplication (CM). While being inefficient in bulk semiconductors this process is enhanced in quantum dots, although not sufficiently high to considerably boost the power output of practical devices. Here we demonstrate that thick-shell PbSe/CdSe nanostructures can show almost a fourfold increase in the CM yield over conventional PbSe quantum dots, accompanied by a considerable reduction of the CM threshold. These structures enhance a valence-band CM channel due to effective capture of energetic holes into long-lived shell-localized states. The attainment of the regime of slowed cooling responsible for CM enhancement is indicated by the development of shell-related emission in the visible observed simultaneously with infrared emission from the core.

Original languageEnglish
Article number4148
JournalNature Communications
Volume5
DOIs
Publication statusPublished - Jun 18 2014

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Quantum Dots
multiplication
Semiconductor quantum dots
quantum dots
Solar Energy
Cooling
Semiconductors
Hot carriers
Nanostructures
Valence bands
Photons
Kinetic energy
Solar energy
Solar cells
Electrons
Semiconductor materials
Infrared radiation
Equipment and Supplies
cooling
solar energy

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Chemistry(all)
  • Physics and Astronomy(all)

Cite this

Cirloganu, C. M., Padilha, L. A., Lin, Q., Makarov, N. S., Velizhanin, K. A., Luo, H., ... Klimov, V. I. (2014). Enhanced carrier multiplication in engineered quasi-type-II quantum dots. Nature Communications, 5, [4148]. https://doi.org/10.1038/ncomms5148

Enhanced carrier multiplication in engineered quasi-type-II quantum dots. / Cirloganu, Claudiu M.; Padilha, Lazaro A.; Lin, Qianglu; Makarov, Nikolay S.; Velizhanin, Kirill A.; Luo, Hongmei; Robel, Istvan; Pietryga, Jeffrey M.; Klimov, Victor I.

In: Nature Communications, Vol. 5, 4148, 18.06.2014.

Research output: Contribution to journalArticle

Cirloganu, CM, Padilha, LA, Lin, Q, Makarov, NS, Velizhanin, KA, Luo, H, Robel, I, Pietryga, JM & Klimov, VI 2014, 'Enhanced carrier multiplication in engineered quasi-type-II quantum dots', Nature Communications, vol. 5, 4148. https://doi.org/10.1038/ncomms5148
Cirloganu CM, Padilha LA, Lin Q, Makarov NS, Velizhanin KA, Luo H et al. Enhanced carrier multiplication in engineered quasi-type-II quantum dots. Nature Communications. 2014 Jun 18;5. 4148. https://doi.org/10.1038/ncomms5148
Cirloganu, Claudiu M. ; Padilha, Lazaro A. ; Lin, Qianglu ; Makarov, Nikolay S. ; Velizhanin, Kirill A. ; Luo, Hongmei ; Robel, Istvan ; Pietryga, Jeffrey M. ; Klimov, Victor I. / Enhanced carrier multiplication in engineered quasi-type-II quantum dots. In: Nature Communications. 2014 ; Vol. 5.
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