A fundamental understanding of interfacial charge transfer at donor-acceptor
interfaces is very crucial as it is considered among the most important dynamical
processes for optimizing performance in many light harvesting systems, including
photovoltaics and photo-catalysis. In general, the photo-generated singlet excitons in
photoactive materials exhibit very short lifetimes because of their dipole-allowed spin
radiative decay and short diffusion lengths. In contrast, the radiative decay of triplet
excitons is dipole forbidden; therefore, their lifetimes are considerably longer. The
discussion in this thesis primarily focuses on the relevant parameters that are involved in
charge separation (CS), charge transfer (CT), intersystem crossing (ISC) rate, triplet state
lifetime, and carrier recombination (CR) at silver nanocluster (NCs) molecular-acceptors
interfaces. A combination of steady-state and femto- and nanosecond broadband
transient absorption spectroscopies were used to investigate the charge carrier dynamics
in various donor-acceptor systems.
Additionally, this thesis was prolonged to investigate some important factors that
influence the charge carrier dynamics in Ag29 silver NCs donor-acceptor systems, such as
the metal doping and chemical structure of the nanocluster and molecular acceptors.
Interestingly, clear correlations between the steady-state measurements and timeresolved
spectroscopy results are found. In the first study, we have investigated the
interfacial charge transfer dynamics in positively charged meso units of 5, 10, 15, 20-tetra (1-
methyl-4-pyridino)-porphyrin tetra (p-toluene sulfonate) (TMPyP) and neutral charged 5, 10,
15, 20-tetra (4-pyridyl)-porphyrin (TPyP), with negatively charged undoped and gold (Au)-
doped silver Ag29 NCs. Moreover, this study showed the impact of Au doping on the charge
carrier dynamics of the system. In the second study, we have investigated the interfacial
charge transfer dynamics in [Pt2 Ag23 Cl7 (PPh3)10] silver NCs doped with platinum (Pt), with
neutral charged 5, 10, 15, 20-tetra (4-pyridyl)-porphyrin (TPyP). Here, we evaluated the
effects of Pt (II) doping on the interfacial charge-transfer dynamics between TPyP and silver
NCs.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/625307 |
| Date | 07 1900 |
| Creators | Almansaf, Abdulkhaleq |
| Contributors | Mohammed, Omar F., Physical Science and Engineering (PSE) Division, Bakr, Osman, Takanabe, Kazuhiro |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | 2018-08-03, At the time of archiving, the student author of this thesis opted to temporarily restrict access to it. The full text of this thesis became available to the public after the expiration of the embargo on 2018-08-03. |
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