Optical excitations in organic and inorganic semiconductors (OPTEXC) - Understanding and control through external stimuli
Project Area: Controlling decoherence in the singlet fission process..
We aim at controlling decoherence in the singlet fission process through molecular design and the influence of external control over the evolving film morphology. In contrast to the commonly used crystalline materials, we use an “amorphous” intramolecular triplet host. In these compounds, the dephasing can be controlled by manipulating the local energy landscape molecular reorganisation in the excited state.
The role of inter- and intramolecular interactions in the singlet fission
Supervisor: D. Jones, Chemistry, UoM; H. Oberhofer, Theoretical Physics, UBT
C0-Supervisor: A. Köhler, Experimental Physics, UBT
I have a position available: Incorporation of SF materials into solar cells offers the potential to reduce the cost per Watt of delivered power by up to 25-30%. In this project, we will synthesise intramolecular SF chromophores with secondary self-assembly characteristics, characterise their SF properties, and determine the impact of molecular orientation of SF yields. The role of the bridging linker between SF chromophores and the nature of the solubilising side-chains will be examined. Please contact A/Prof David Jones if you have a strong background in organic synthesis and wish to provide materials into this great program.
A/Prof. David Jones is part of the extension of the Australian Centre for Advanced Photovoltaics (ACAP) and is looking for 6-8 new PhD applicants for synthetic organic chemistry research.
The positions start in 2023 and applicants should apply through the normal application process [https://study.unimelb.edu.au/study-with-us/graduate-research]. Excellent students will have the opportunity for joint PhD positions with international collaborators.
Typical areas of research are discussed below.
Project 1
Controlled synthesis of semiconducting polymers.
Traditional step-growth polymerisation of high performing organic semiconducting polymers normally leads to a large variation n secular weight and inclusion of numerous defects, i.e. homo-coupled products. We have been developing methods for highly controlled synthesis of high performing polymers, leading to controlled pseudo-living polymerisations. This allows us to generate defined molecular weight polymers or oligomers, with few defects. We can use these materials for fundamental studies on exciton formation and semiconductor performance.
Project 2
High K-dielectric oligomers for organic electronic applications-towards ferroelectric semiconducting polymers.
Significant energy losses in organic solar cells are a result of the S1 excited state having strong coulombic binding. Inorganic solar cells, for example silicon, gallium arsenide, perovskite etc., have lower energy losses because of a higher dielectric constant in the materials supports charge separation. It has been proposed that significant advances in organic solar cell device efficiency can be achieved if organic semi-conductors with higher dielectric constants can be synthesised. In this study we look to synthesise high K-dielectric oligomers for analysis, and inclusion in higher organic semiconductors.
Project 3
Singlet Fission enhanced solar cells- Breaking the Schockley-Quiesser Limit
We have recently demonstrated that discotic liquid crystalline organic semiconductors can be design to promote singlet fission, that is taking the energy of a singlet exciton generated on absorption of a high energy photon to generate two triplet excitons. It has been predicted that we should be able to increase solar cell efficiencies from 32 to 45% power conversion efficiency, or by 40%. I am looking for an excellent student to synthesise new materials, complete preliminary characterisation, and incorporate them into solar cells.
Project 4
Discotic liquid crystalline intra-molecular singlet fission materials.
We have recently demonstrated that discotic liquid crystalline organic semiconductors can be design to promote singlet fission, that is taking the energy of a singlet exciton generated on absorption of a high energy photon to generate two triplet excitons. It has been predicted that we should be able to increase solar cell efficiencies from 32 to 45% power conversion efficiency, or by 40%. We would like to know if this is a generic property of discotic liquid crystalline materials and therefore need to complete significant structure property studies. This is an excellent research opportunity for someone interested in the design, synthesise, characterisation and application of advanced organic semiconductors.