The next generation of solar cells based on organic semiconductors can be solution processed over large areas leading to solar cells that are cheaper than current technology as well as being lighter and flexible. Current state-of-the-art performance for organic solar cells have efficiencies up to 19% and these are typically based on a mixture of two or more semiconductor materials. This mixture is required for the efficient generation of free charges but increases the complexity of the device as the morphology is hard to control. As a consequence, there is interest in developing organic semiconductor materials that exhibit intrinsic charge generation without the need for mixing with a separate material. Understanding the photo-physical properties of these novel solar materials, in other words, the series of steps that need to occur for light to be converted into charge, remains a challenge.
The aim of this project is to use time-resolved spectroscopy to probe the photo-physical properties of organic semiconductors for single-material solar cells. The use of time-resolved optical spectroscopy is critical as the charge generation processes occur on very short timescales that cannot typically be observed from electrical measurements. Specifically, transient absorption and time-resolved terahertz spectroscopy will be employed to probe the formation and recombination of charge carriers on timescales from the femtosecond to the microsecond. The use of time-resolved spectroscopy will provide unique insights into the mechanism of charge generation in the next generation of solar cells, which in turn will guide the design of future materials and more efficient solar cells.
The success of this research proposal will deliver the following outcomes:
• Novel methods and techniques for probing the photo-physical properties of solar cell materials
• New fundamental knowledge of how charge is generated in organic semiconductor materials.
• Design rules for designing solar materials and processes for maximising their performance
Information for applicants
Experience in semiconductor physics and/or optical spectroscopy
Prior experience in organic electronics, such as, film preparation, device fabrication and testing
Expected qualifications (Course/Degrees etc.)
Master’s or equivalent in physics/physical chemistry with a thesis/research component
Additional information for applicants
note: i-students must have own scholarship to apply (CSIR, UCG-NET, etc)