Photoinduced hole transfer in QD–phthalocyanine hybrids
| Autor: | A. Schramm, M. Arvani, Nikolai V. Tkachenko, Alexander Efimov, Donald Lupo, Kirsi Virkki, Fawzi Abou-Chahine |
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| Přispěvatelé: | Tampere University, Department of Electronics and Communications Engineering, Research group: Laboratory for Future Electronics, Department of Chemistry and Bioengineering, Research group: Supramolecular photochemistry, Research group: Semiconductor Technology and Applications |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Quenching
116 Chemical sciences General Physics and Astronomy 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences 114 Physical sciences 0104 chemical sciences chemistry.chemical_compound Condensed Matter::Materials Science chemistry Quantum dot Computational chemistry Excited state Ultrafast laser spectroscopy Valence band Phthalocyanine Steady state (chemistry) Physical and Theoretical Chemistry 0210 nano-technology HOMO/LUMO |
| Popis: | A series of CdSe quantum dot (QD)–phthalocyanine (Pc) hybrids were synthesized and their photophysics was studied using steady state and time-resolved spectroscopic methods. Emission of QDs was progressively quenched upon increasing the concentration of Pc in the hybrids. A detailed transient absorption study of the hybrids revealed that the mechanism of quenching is charge separation, resulting in the formation of hybrids with negatively charged QDs and the Pc cation. Direct photo-excitation of Pc did not show any detectable interaction between the excited state of Pc and the QD to which it is attached. An explanation is proposed, based on the suggestion that the energy of the lowest unoccupied molecular orbital (LUMO) of Pc is lower than the lower edge of the QD conduction band, while the energy of the highest occupied molecular orbital (HOMO) of Pc is sufficiently higher than the high energy edge of the QD valence band (VB), thus permitting hole transfer from the QD VB to the Pc HOMO after photo-excitation of QDs. acceptedVersion |
| Databáze: | OpenAIRE |
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