Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 17 of 17 for “"Charge Transfer (CT)"”.
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Simulating exciton dynamics in organic semiconductors
Organic semiconductors are carbon-based semiconductors with number of unique benefits over traditional semiconductors such as low production costs, versatile synthesis processes, and high portability. Unlike traditional crystalline semiconductors that exhibit high level of homogeneity, organic …
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The synthesis of novel organometallic materials.
Due to their highly interesting electroactive properties, complexes based on the sulphur heterocycle DMIT have been studied extensively for several decades. The literature is abundant with materials exhibiting semiconducting and metallic properties and up to early 2000 there are eight examples of …
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Synthesis and Photophysics of Varied Substituted DPNDs for Potential PDT Applications
Understanding how molecular architecture and solvent polarity govern excited-state dynamics is fundamental to developing functional chromophores for photo-energy conversion and manipulation for opto-electronic applications. Here, the photophysical properties of three dipyrrolonaphthyridinedione …
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Kinetics and Mechanism of the Catalysis of the Decomposition of Hydrogen Peroxide by Schiff Base Complexes of Copper(II).
<p>Spectroscopic studies have been used to describe the mechanism of the decomposition of hydrogen peroxide by solutions of a dimeric Cu(II) complex of a dissymetric Schiff base, [CuSALAD]<sub>2</sub>.H<sub>2</sub>O, and imidazole or methyl substituted imidazoles, B, which form monomeric …
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Thermally Activated Delayed Fluorescence Emitters: Molecular Design, Photophysics, and Sensing Application
Thermally activated delayed fluorescence (TADF) is a strategy for harvesting both singlet and triplet excitons in some purely organic emitters and is attracting increasing interest beyond their use in organic light-emitting diodes (OLEDs), including chemical sensing. In this thesis, coumarin-based …
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Surface-enhanced Raman scattering and electron spectroscopic studies of copper and silver surfaces.
… approach taken in these investigations is to directly compare the SERS abilities of Cu and Ag surfaces using both SERS and electron spectroscopy. One set of experiments has been directed toward studying the contribution of the charge transfer (CT) mechanism to the SERS of pyridine adsorbed on Cu …
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Electronic Structure Modelling of Singlet Fission in Organic Photovoltaics
… and theoretical attention, different aspects of the process are still not fully understood. The main reason for this is that singlet fission is characterised by a complex interplay of electronic states, vibrational modes and electrostatic screening effects. In this thesis we employ …
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Effects of Low Temperature and Structure on the Photophysics of Alkylammonium Lead Halide Semiconductors
… investigates some of the physics of semiconducting low-dimensional structures at low temperatures, as well as investigating the effects of defects on low-dimensional structures and magnetic fields on charge recombination in organic photovoltaics (OPVs). The applications of the systems studied …
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Enhancing the Third-Order Nonlinear Optical Properties of Porphyrins and Molecular Wires
… on thick substrates was refined for the characterization of films less than 100 nm thick and applied to ITO films ~25 nm thick. It was found that the third-order nonlinear susceptibility of ITO, χ(3)ITO, is purely electronic at 900 - 1300 nm (11000 - 7700 cm-1) and has a value of (2.16 ± 0.18) …
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Modification of exciton energies and dynamics for thin film optoelectronics
Organic and nano-crystal thin film semiconductors have proven to be effective materials for a range of optoelectronic applications including light emitting diodes, visible wavelength lasers, photovoltaics, and sensors. Mediating photons and charges, excitons are responsible for electrical and …
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Describing Charge Transfer in Extended Donor-Acceptor Systems with Density Functional Theory
… problem of (time-dependent) density functional theory ((TD)DFT) that traditional functionals severely underestimate charge transfer (CT) excitations. In particular, the theoretical description of donor-acceptor (DA) systems is plagued by this shortcoming. DA systems are frequently used …
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Design, Synthesis and Spectroscopy of Highly Absorptive Chromophores Based on the Bis(tridentate)metal-ethyne-(porphinato)metal Molecular Framework for Solar Energy Conversion
… that include dye-sensitized solar cells, photoelectrochemical cells, and photo-redox catalysis. In this dissertation, the design, synthesis and spectroscopy of a series of different highly absorptive chromophoric systems based on the bis(tridentate)metal-ethyne-(porphinato)metal molecular …
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Photophysical Studies of Active Layer Compositions in Organic Solar Cells
… solar cells (OSCs), based on organic semiconductors, have also recently attracted much attention within the Internet-of-Things community because of their ability to be integrated into low-energy off-grid devices and because of their spectral sensitivity making them good candidates for indoor …
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Electronic excited states in quasi- one- dimensional organic solids with strong coupling of Frenkel and charge-transfer excitons
This work offers a concept to predict and comprehend the electronic excited states in regular aggregates formed of quasi-one-dimensional organic materials. The tight face-to-face stacking of the molecules justifies the idealization of the crystals and clusters as weakly interacting stacks with …
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The role of spatial size and orientation of electronic wavefunction in exciton dissociation at van der Waals interfaces
… is its relative low performance in solar to electrical energy conversion compared to inorganic counterparts such as Si solar cells. Unlike typical inorganic materials in which free carriers are generated directly by the light absorption, excitons, Coulombic bound electron-hole pairs, are created …
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Part I: Circular dichroism studies of optically active charge transfer complexes. Part II: vapor phase and solvent dependence circular dichroism studies of some terpenes, α-phenylethanol, and α-phenylethylamine
<p>The circular dichroism charge transfer (CT) spectra of the achiral acceptors TCNE, DDQ, and Vitamin K<sub>3</sub> with chiral donors such as terpenes, steroids and β-phenylethylamine derivatives in methylene chloride at 27° were investigated. A new transition not attributable to either component …
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Electrochemical Studies of Reactions in Small Volumes Less Than 1 Femto Litres.
<p>Electrochemical methods have been used to study electron transfer reactions at the interface between an aqueous phase of less than 1 femto liters in volume and a bulk organic phase. The small aqueous phase is formed at the end of a slightly recessed platinum electrode. When a negative potential …