Gerard J. Wilson

Organic Solar Cells Using a High‐Molecular‐Weight Benzodithiophene–Benzothiadiazole Copolymer with an Efficiency of 9.4%

A high molecular weight donor-acceptor conjugated polymer is synthesized using the Suzuki polycondensation method. Using this polymer, a single-junction bulk-heterojunction solar cell is fabricated giving a power conversion efficiency of 9.4% using a fullerene-modified ZnO interlayer at the cathode contact.

All-inorganic quantum-dot light-emitting devices formed via low-cost, wet-chemical processing

The fabrication and characterisation of solution-processed, all-inorganic light-emitting devices incorporating colloidal CdSe/ZnS quantum dots are presented. Using sol–gel synthetic routes, highly luminescent core–shell QDs are embedded between spin-coated p-type NiO and n-type ZnO charge-transport layers. The resulting devices show pure QD electroluminescent emissions with a maximum EL brightness of 249 cd m−2.

RAFT synthesis of linear and star-shaped light harvesting polymers using di- and hexafunctional ruthenium polypyridine reagents

The syntheses of linear and star-shaped light harvesting polymers with well defined structure and narrow molecular weight distribution are described. These polymers have ruthenium polybipyridine moieties as the energy trap cores and styrene functionalized coumarin monomers as the light absorbing antenna chromophores. The polymers have been made by reversible addition–fragmentation chain transfer (RAFT) polymerisation using di- or hexafunctional ruthenium-containing RAFT agents. The resulting ruthenium-containing polymers have narrow molecular weight distribution (polydispersity < 1.1) and exhibit energy transfer efficiencies of up to 60% between the coumarin donor dyes and the ruthenium acceptor chromophores.

Absorption enhancement of oligothiophene dyes through the use of a cyanopyridone acceptor group in solution-processed organic solar cells.

Improvements in the performance of small molecule-based organic solar cells have been reported through the use of a cyanopyridone acceptor group. This acceptor fragment enhances the absorbance of an oligothiophene-based dye and enables the addition of a solubilising alkyl chain that facilitates simple device fabrication from solution.

Singlet and triplet energy transfer processes in ruthenium(II) bipyridine complexes containing covalently bound arenes

Abstract Singlet and triplet energy transfer processes in [Ru(bipy) 2 (4-methyl-4′-(2-arylethyl)-2,2′-bipyridine)] 2+ have been investigated, where aryl = 2-naphthyl (Ru-Naph), 9-anthryl (Ru-Anth) and 1-pyrenyl (Ru-Pyrene). In each case fluorescence from the aromatic chromophore is quenched by intramolecular energy transfer to Ru(bipy) 3 2+ whereas emission from the Ru(bipy) 3 2+ moiety is controlled by the relative energy of its 3 MLCT state and the pendant arene triplet states. Consequently 3 MLCT emission is observed for Ru-Naph whereas it is fully quenched for Ru-Anth. When the two states are isoenergetic (e.g. Ru-Pyrene) a long-lived 3 MLCT emission is observed which delays with the same lifetime as the pyrene triplet state (5.23 μs).

Advanced Materials for Banknote Applications

Australia has spearheaded the worldwide struggle against counterfeiting banknotes over the past 30 years. In the first stage polymer banknotes with transparent windows that contain an optically variable devices (OVDs) were issued. New developments comprise (a) the “self-veryfying banknote” where the interaction of features imprinted in the window e.g., an optical lens, and in another region of the note e.g., microtext only legible under this lens, prove the banknotes authenticity, (b) elaborate inks which for example reveal hidden images under special angles or light intensity, and diffractive OVD elements. Despite the great progress made, the quest for more forgery-proof money remains a continuing effort.

Controlled synthesis of luminescent polymers using a bis-dithiobenzoate RAFT agent

A higher efficiency of excitation energy transfer occurs to a luminescent diphenylanthracenyl acceptor incorporated at the centre, rather than the end, of an acenaphthylene polymer chain.

Mechanisms of Excimer Formation in Poly(acenaphthylene)

Excimer (excited state dimer) formation mechanisms in solution have been investigated for a series of acenaphthyl-containing compounds comprising dimers, higher oligomers, and a poly(acenaphthylene) (PAcN) homopolymer. Excimer fluorescence is observed only for dimers with a threo-diisotactic arrangement of the acenaphthyl groups indicating that interactions between nearest-neighbour chromophores are able to play a role in excimer formation in PAcN. An increase in excimer emission is observed with increasing chain length and attributed to additional excimer formation and energy migration processes.

Synthesis of light harvesting polymers by RAFT methods

Polymers prepared by RAFT polymerisation containing acenaphthyl energy donors and a terminal anthryl energy acceptor have a narrow molecular weight distribution and exhibit excitation energy transfer efficiencies up to 70%.

Excimer geometries in bichromophoric molecules : a theoretical and experimental study of 1,2-(bis-9-anthryl)-ethane

Abstract A detailed study of the photophysics and photochemistry of the bichromophoric molecule 1,2-(bis-9-anthryl)-ethane (A2A) is presented. The ground- and excited-state potential energy hypersurfaces of A2A were calculated using semiempirical methods modified to account for the facile intramolecular excimer formation observed in this molecule. Temperature dependent fluorescence spectra were numerically resolved into the contributions from various underlying components using principal factor analysis. Thesesteady state results were combined with both time resolved experiments and the semiempirical calculations to identify and characterize the various excimer geometries.