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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

Media: Sunday Times
2006-05-20

Sunday Times, 4 June 2006

True leadership may mean admitting disunity
 

In this edited extract from the inaugural King Moshoeshoe Memorial Lecture at the University of the Free State, Professor Njabulo S Ndebele explores the leadership challenges facing South Africa

RECENT events have created a sense that we are undergoing a serious crisis of leadership in our new democracy. An increasing number of highly intelligent, sensitive and committed South Africans, across class, racial and cultural spectrums, confess to feeling uncertain and vulnerable as never before since 1994.

When indomitable optimists confess to having a sense of things unhinging, the misery of anxiety spreads. We have the sense that events are spiralling out of control and that no one among the leadership of the country seems to have a definitive handle on things.

There can be nothing more debilitating than a generalised and undefined sense of anxiety in the body politic. It breeds conspiracies and fear.

There is an impression that a very complex society has developed, in the last few years, a rather simple, centralised governance mechanism in the hope that delivery can be better and more quickly driven. The complexity of governance then gets located within a single structure of authority rather than in the devolved structures envisaged in the Constitution, which should interact with one another continuously, and in response to their specific settings, to achieve defined goals. Collapse in a single structure of authority, because there is no robust backup, can be catastrophic.

The autonomy of devolved structures presents itself as an impediment only when visionary cohesion collapses. Where such cohesion is strong, the impediment is only illusory, particularly when it encourages healthy competition, for example, among the provinces, or where a province develops a character that is not necessarily autonomous politically but rather distinctive and a special source of regional pride. Such competition brings vibrancy to the country. It does not necessarily challenge the centre.

Devolved autonomy is vital in the interests of sustainable governance. The failure of various structures to actualise their constitutionally defined roles should not be attributed to the failure of the prescribed governance mechanism. It is too early to say that what we have has not worked. The only viable corrective will be in our ability to be robust in identifying the problems and dealing with them concertedly.

We have never had social cohesion in South Africa — certainly not since the Natives’ Land Act of 1913. What we definitely have had over the decades is a mobilising vision. Could it be that the mobilising vision, mistaken for social cohesion, is cracking under the weight of the reality and extent of social reconstruction, and that the legitimate framework for debating these problems is collapsing? If that is so, are we witnessing a cumulative failure of leadership?

I am making a descriptive rather than an evaluative inquiry. I do not believe that there is any single entity to be blamed. It is simply that we may be a country in search of another line of approach. What will it be?

I would like to suggest two avenues of approach — an inclusive model and a counter-intuitive model of leadership.

In an inclusive approach, leadership is exercised not only by those who have been put in some position of power to steer an organisation or institution. Leadership is what all of us do when we express, sincerely, our deepest feelings and thoughts; when we do our work, whatever it is, with passion and integrity.

Counter-intuitive leadership lies in the ability of leaders to read a problematic situation, assess probable outcomes and then recognise that those outcomes will only compound the problem. Genuine leadership, in this sense, requires going against probability in seeking unexpected outcomes. That’s what happened when we avoided a civil war and ended up with an “unexpected” democracy.

Right now, we may very well hear desperate calls for unity, when the counter-intuitive imperative would be to acknowledge disunity. A declaration of unity where it manifestly does not appear to exist will fail to reassure.

Many within the “broad alliance” might have the view that the mobilising vision of old may have transformed into a strategy of executive steering with a disposition towards an expectation of compliance. No matter how compelling the reasons for that tendency, it may be seen as part of a cumulative process in which popular notions of democratic governance are apparently undermined and devalued; and where public uncertainty in the midst of seeming crisis induces fear which could freeze public thinking at a time when more voices ought to be heard.

Could it be that part of the problem is that we are unable to deal with the notion of opposition? We are horrified that any of us could be seen to have become “the opposition”. The word has been demonised. In reality, it is time we began to anticipate the arrival of a moment when there is no longer a single, overwhelmingly dominant political force as is currently the case. Such is the course of history. The measure of the maturity of the current political environment will be in how it can create conditions that anticipate that moment rather than seek to prevent it. We see here once more the essential creativity of the counter-intuitive imperative.

This is the formidable challenge of a popular post-apartheid political movement. Can it conceptually anticipate a future when it is no longer overwhelmingly in control, in the form in which it is currently, and resist, counter-intuitively, the temptation to prevent such an eventuality? Successfully resisting such an option would enable its current vision and its ultimate legacy to our country to manifest in different articulations, which then contend for social influence. In this way, the vision never really dies; it simply evolves into higher, more complex forms of itself. Consider the metaphor of flying ants replicating the ant community by establishing new ones.

We may certainly experience the meaning of comradeship differently, where we will now have “comrades on the other side”.

Any political movement that imagines itself as a perpetual entity should look at the compelling evidence of history. Few movements have survived those defining moments when they should have been more elastic, and that because they were not, did not live to see the next day.

I believe we may have reached a moment not fundamentally different from the sobering, yet uplifting and vision-making, nation-building realities that led to Kempton Park in the early ’90s. The difference between then and now is that the black majority is not facing white compatriots across the negotiating table. Rather, it is facing itself: perhaps really for the first time since 1994. Could we apply to ourselves the same degree of inventiveness and rigorous negotiation we displayed leading up to the adoption or our Constitution?

This is not a time for repeating old platitudes. It is the time, once more, for vision.

In the total scheme of things, the outcome could be as disastrous as it could be formative and uplifting, setting in place the conditions for a true renaissance that could be sustained for generations to come.

Ndebele is Vice-Chancellor of the University of Cape Town and author of the novel The Cry of Winnie Mandela

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