Surface Effects on Pyrene Luminescence Excitation
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2020-08-10 |
| Journal | ACS Applied Electronic Materials |
| Authors | Jacob R. Ritter, MarĂlia Caldas, Tales J. da Silva, Arrigo Calzolari, Matthew D. McCluskey |
| Institutions | Istituto Nanoscienze, Universidade de SĂŁo Paulo |
| Citations | 12 |
Abstract
Section titled âAbstractâPyrene is a polycyclic aromatic hydrocarbon with fluorescence in the 370-400 nm range. The optical properties of pyrene deposited on different substrates were investigated from experimental and theoretical points of view. In contrast to prior studies of surface-enhanced fluorescence, in this work all substrates were semiconductors or insulators. Experimentally, the intensity of photoluminescence (PL) and PL excitation (PLE) spectra were investigated. PLE spectra of pyreneâs monomer emission show that the intensities of the two main absorption peaks vary according to the chosen substrate. Here, calculations for pyrene on zinc sulfide (ZnS) and surface-oxidized diamond suggest that this connection arises from the alignment of the pyrene electronic levels relative to the band edges of the substrate. The absorption peak at 272 nm (4.56 eV) is shown to depend on the HOMO-1âLUMO orbital contribution while the 335 nm (3.70 eV) peak depends upon the HOMOâLUMO transition. When the HOMO-1 level falls inside the substrate valence band, as in the case of ZnS, there is significant hybridization of the molecular state with surface states that causes an enhancement of the 272 nm peak. For pyrene on diamond, however, the HOMO-1 level falls in the substrate bandgap, leading to negligible hybridization and thus no enhancement.
Tech Support
Section titled âTech SupportâOriginal Source
Section titled âOriginal SourceâReferences
Section titled âReferencesâ- 2019 - Surface Science: Foundations of Catalysis and Nanoscience
- 2019 - Polymers and Polymeric Composites: A Reference Series