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01 March 2024 | Story Leonie Bolleurs | Photo SUPPLIED
Dr Lucas Erasmus
Dr Lucas Erasmus, Junior Researcher in the Department of Physics, has just returned from Belgium where he had his public defence of a joint PhD with Ghent University, titled: Luminescent solar concentrators – where Sm2+ doped phosphors shine.

“I like taking what I have learned from literature and going to the laboratory to test it. Sometimes the results surprise me, leading to additional experiments or refining. This process could continue for several months and even years, with me slowly building the puzzle. And finally, one day, all the pieces come together, and everything becomes very clear to me as a physicist. And if I am lucky, I will have the privilege of knowing a secret about nature that nobody else has known up to this point. However, as an innovator, I am tasked with using this new knowledge to develop ways to manipulate nature to deliver a helpful device.”

These are the thoughts of Dr Lucas Erasmus, Junior Researcher in the Department of Physics at the University of the Free State (UFS), who has just returned from Ghent, Belgium, where he had his public defence of a joint PhD with Ghent University, titled: Luminescent solar concentrators – where Sm2+ doped phosphors shine.

The research project is part of a bilateral collaboration between the Department of Physics at the UFS and the Department of Solid State Sciences at Ghent University. In this study, the strengths, experience, and resources of both research groups – experienced in developing luminescent materials for various applications – are used to ensure a stronger final product. To meet the requirements stipulated in the cooperation agreement between the two institutions for the joint supervision and certification of Dr Erasmus’ doctoral studies, research was conducted both at the UFS and at Ghent University.

Dr Erasmus’ research is significant in the light of rising energy prices, energy scarcity, and the pursuit of a carbon-free society, where there are strong incentives to develop new and renewable energy sources.

Combining windows and solar cells increase their relevancy in many applications

He says that although solar panels play an essential role in renewable energy – since they provide a route to directly convert solar radiation into electricity – there are limitations to installing conventional panels, which are bulky, rigid, and opaque. He believes that combining windows and solar cells could increase their relevance in the built environment, agricultural sector, and modern consumer electronics.

Explaining about the luminescent solar concentrator (LSC) in his study, he states that it is a device used as a large-area solar radiation collector that converts and emits radiation. The emitted radiation is directed to photovoltaic cells located in the small side area of the device. According to him, a basic LSC consists of a transparent waveguide with an embedded luminescent material and a strategically placed photovoltaic cell on the edge.

Dr Erasmus continues, “The large area of the waveguide collects a portion of the solar radiation, while the luminescent material absorbs the energy and downshifts it to longer wavelengths. Internal reflection directs the emitted photons towards smaller areas on the sides where the photovoltaic cells are used to convert the concentrated light into electricity.”

In his view, creating a large and efficient LSC is a challenging endeavour that requires an in-depth study of multiple domains. “This includes developing and optimising the luminescent material, studying its behaviour and the characteristics of the waveguide, and finally adding these two components and developing, characterising, and simulating the hybrid device,” he remarks.

“While the current prototype we have developed delivers good results, it is still far from perfect and not commercially viable,” he says, stating that this study could, however, serve as a guide for future researchers interested in developing LCSs. Dr Erasmus believes the underlying science behind the results contributes to a general understanding of the materials, making this study valuable to other fields and contributing to the larger body of science. At the end of the study, he also makes some recommendations for future research in this field. 

Study a reflection of theoretical knowledge and a practical system

The public defence consisted of both an internal and an external defence. The internal defence took place in January at the UFS between Dr Erasmus and the examination committee. The external defence occurred at Ghent University and was also open to the broader public. Also present at this event in Belgium were colleagues from the UFS – Prof David Motaung, an examiner; Prof Koos Terblans, co-supervisor; and Prof Hendrik Swart, supervisor for the PhD thesis.

Dr Erasmus’ experience of the oral examination was that the examiners were primarily positive in their critique but also thorough in their questioning. According to him, some of their remarks pointed out that they were impressed with the meticulous planning, execution, and interpretation of the experimental results and that the researchers involved ensured that any parameter that might have influenced the device was maximised. “Moreover, they liked the fact that I went all the way from theoretical knowledge to a practical system. The examiners also noted that the study compares well with the current state-of-the-art research in the field,” adds Dr Erasmus.

He says that having the public defence in Belgium was a once-in-a-lifetime experience, allowing him to interact and deliberate directly with the examiners and communicate their findings and conclusions to the broader public. Dr Erasmus hopes that this will lead to stronger collaboration and better public sentiment toward spending funding for scientific projects.

For future steps, he states, the research group involved in the project plans to continue this research by further increasing the device's efficiency. “To this end, we have already developed another luminescent material that can address some of the challenges we encountered while developing the first prototype device. This forms part of the work that Johané Odendaal is doing in her master’s degree, of which I am a co-supervisor. We also plan to enlarge the scope of our research to consider the challenges that are currently hampering the next generation of photovoltaic cells and to find ways in which we could address these issues,” comments Dr Erasmus.

News Archive

Trauma, Forgiveness, and Reconciliation Studies produces a literary hat trick
2015-12-17

Description: Samantha book cover Tags: Samantha book cover

Three scholars. Three books. One research unit.

Two post-doctoral fellows and a PhD student from Trauma, Forgiveness and Reconciliation (TFR) Studies at the University of the Free State (UFS) have each achieved author-status. During December 2015, Drs Samantha van Schalkwyk and Kim Wale, as well as Naleli Morojele will have their books on the shelves.

Description: Naleli Morojele book cover Tags: Naleli Morojele book cover

Dr Van Schalkwyk, PhD in Psychology (UFS, 2014), is leading co-editor of the book A Reflexive Inquiry into Gender Research: Towards a New Paradigm of Knowledge Production & Exploring New Frontiers of Gender Research in Southern Africa. The book is a product of an international symposium she organised in 2013. Dr Van Schalkwyk has made prolific contributions during her three years at the UFS: speaking at two international conferences, and publishing her research in internationally-accredited peer-reviewed journals. In addition, she is also heading a major research project on Gender Reconciliation, based at the university.

Dr Wale is a graduate of the University of London with a PhD (2013) in post-conflict development. Her forthcoming book, South Africa's Struggle to Remember: Contested Memories of Squatter Resistance in the Western Cape is based on her doctoral research. Now that Dr Wale’s book is finished, she will be working with Prof Pumla Gobodo-Madikizela on the analysis of research data collected for a study on transformation – as well as resistance to it – in students’ residences.

 Description: Kim Wale book cover Tags: Kim Wale book cover

Naleli Morojele received her Master of Arts in African Studies in 2014 from the UFS. Her dissertation research was on women political leaders in post-conflict countries, with data collected in South Africa and Rwanda. The review comments on her thesis prompted her to consider turning her research into a book. She spent seven months on this project with support from a global network of mentors affiliated with TFR Studies. The product is the book, Women Political Leaders in Rwanda and South Africa: Narratives of Triumph and Loss. Morojele is currently a PhD candidate. Her study focuses on university women, and explores women’s gender identity in the post-apartheid context.

“I am very excited about the work that these young women have produced,” says Prof Gobodo-Madikizela. “Dr Van Schalkwyk has already been invited by Palgrave Macmillan to consider a contract with the publisher to turn her PhD thesis into a book. It is going to be a very busy and productive year for her.”

A bumper book launch in mid-January 2016 is in the pipeline.

 

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