A Don in the Department of Physics, College of Physical Sciences (COLPHYS), Professor Gboyega Adebayo, has disclosed that some special types of compounds, known as Heusler Alloys, which are semiconductors in nature, can be used as small voltage power generations. A Heusler Alloy is a three-element compound, which if combined in the right proportions, results in a new material with better properties and consequently if two Heusler Alloys are joined together in what is known as Thermoelectric Heterostructure, the combined alloys will generate small electric current due to temperature gradient between the alloys. Although, the power generated in this way is very small and cannot power a home, but can find applications in devices or appliances using 2-5Volts.
Professor Adebayo, who is also the Head, Department of Physics in the University, said that such heterostructures were already being fabricated in university laboratories in developed countries. Many of the fabrications depend largely on theoretical calculations/results attained mainly from the fields of Materials Science and Condensed Matter Physics and that one good advantage is the fact that the fabrications are cheap and may also be possible for Nigerian scientists to fabricate if their laboratories are equipped. He noted that “In this part of the world, where we don't have industries or laboratories that could fabricate semiconductors, we might not feel the effects so quickly, but our scientists can contribute to this fast-growing research field by engaging in theoretical calculations that predict properties of Heusler Alloys”. He, however, stressed that he was aware that some researchers can fabricate 2-Dimensional Semiconductors in some Nigerian universities, but the properties of a 2-Dimensional material could be very different from that of corresponding bulk material.
Professor Adebayo, a specialist in Computational Condensed Matter Physics, noted that Physics is divided into two main parts: Experimental Physics and Theoretical Physics, adding that in Theoretical Physics, “we rely on theories to predict the behaviour or properties of material while Experimental Physics practicalise and come up with new materials”. According to him, “What we do in some areas of Condensed Matter Physics or Materials Science is to try and combine three or four elements of the period table to make one improved materials, which can be used as semiconductor materials/components. We are doing this theoretically and not experimentally. The first problem we face when we do theoretical physics is making accurate pronouncement on something you don’t know or something that you have never seen. For example, if I should combine silicon or germanium with two/three other materials, we know from experience that the properties of the new material would not be the same as that of silicon nor that of germanium. The new properties would be entirely different. Therefore, making accurate predictions is usually very problematic”
According to him, as a “Theoretical Physicist, making good predictions would be made to say which material is good for which purpose. Accurate predictions would guide Applied scientists, Materials scientists or Engineers in making new materials. It might be a difficult task, but what we do is to apply the well-established physics laws and theories, then we would see what the new properties would be. There would be some other conditions, which you, as a Theoretical Physicist, must think of. This actually does not end here as some of us that are into theory use computational methods, which mainly means simulations”. He described simulations as mimicking material properties using certain steps and testing on a computer; whether the materials have some kind of properties that would be useful or not. “When you are doing simulations, it’s not just your thinking; you have to combine what the Physicists say with your own thinking. You also find how to code because if you can’t code all these theories, there is no way you can simulate the properties of materials”, he noted. He added that “As difficult as the process looks, a Theoretical Physicist has one advantage which is, he doesn’t have to wait till he has very large equipment before he can do his research. All he needs is to know the theories and know how to think well to get what the theories would predict and so on”.
He added that we are very fortunate to have a very solid graduate programme in Physics, as many of these studies are possible partly because we have brilliant and hard working postgraduate students. I am particularly blessed with graduate students who excel in research. Commenting on a project by an M.Sc student, Mr. Ridwan Agbaoye, who had just completed his work and currently visiting the International Centre for Theoretical Physics in Italy, saying “It is possible to have some organic materials which are semiconductors and could find applications as screen of phones, smart wristwatches, solar panels and on the new generation of flat screens television called the Organic Light Emitting Diode (OLED)”. Professor Adebayo further stated that the student researched an organic semiconductor, called Poly(3,4)-ethylenedioxythiophene (PEDOT), noting that what Mr. Agbaoye did was to theoretically study the elastic and thermodynamic properties of PEDOT among other things. “People have done so many things on PEDOT, but there are still many aspects of it that people have not touched.
Highlighting other benefits of PEDOT, the Theoretical Physicist said it was possible for researchers to combine one or more elements with PEDOT to have an improved compound. According to him, “Part of what we do is to theoretically see how to improve on the properties of some semiconductors, such that they could be more useful to make new materials. It is when new materials are discovered that Applied Scientists could now see how to incorporate the materials into Integrated Circuit (IC) which are useful in devices such as phones, televisions and radios, among others”. He added that in Physics, there is a slogan that says, “Physics today is the technology of tomorrow”. According to him, “What that means is that people may not feel the effects of physics research until 10 or more years later. An example of this is Albert Einstein’s work which took more than 50 years before people realised it”.
He further stated that, “If you look at developed countries, they fund basic sciences because they know that technology of many things depend on how the scientists were able to master basic sciences. So, I would say that the University or government should encourage people in the fields of Physics and Mathematics. We shouldn’t say that the common man on the streets has not been feeling the impact of what we are doing presently. It doesn’t mean that we shouldn’t pay attention to the basic sciences”. According to him, “Corn and Gari sellers on the streets carry sophisticated phones, which were made possible as results of researches from basic sciences performed years or decades ago. So, the truth is that people should not look at us as doing abstract things as the time would come when you'll see the effects of all the things we are doing”.
He, however, mentioned some of the challenges faced by Theoretical Physicists as the same faced generally by other scientists. Professor Adebayo stated that although, doing a theoretical work does not require large equipment to work with, some simulations could not be done on normal laptops or desktop computers as several millions of calculations are needed to be performed in a matter of seconds/minutes. Therefore, faster machines, known as Clusters or High Performance Clusters are required. He described clusters as very fast and accurate computer machines, which could do millions of calculations within seconds, stressing that to have access to clusters, one would need to scout abroad as there is no university or Centre that has it in Nigeria. According to him, “We have to scout around the world to see where they have clusters and beg to use it for few months for us to have some calculations done. From here, it is possible for me to connect to any cluster in any part of the world through the Internet and do my calculations from my table”.
He, therefore, stated that the major challenges are the unavailability of clusters as well as access to it even if permission is granted from abroad. “If there is no power and Internet, we won’t be able to connect or access the clusters over there”, he noted. Using clusters is like someone giving you access to his/her research equipment as a single cluster could costs up to USD40,000 but several scientists can use this single cluster. Professor Adebayo added that part of the challenge is being unable to access online journals. His words; “If you are into Theoretical Physics or you are in Mathematics and you don’t have access to online journals in realtime, you cannot move as much as you should move”. On the folding up of industries in the country and the ways to mitigate against it, he said the erratic power supply in the country should quickly be fixed to forestall further closure. According to him, if power is not fixed in the country, there is no way the nation could move forward industrially.
Professor Adebayo bagged a B.Sc. degree in Physical Sciences in 1992 from FUNAAB; M.Sc. Physics (Condensed Matter Physics) in 1997 from the University of Ibadan and Ph.D. Physics (Condensed Matter Physics) in 2005 also from the University of Ibadan with a year Sandwich Programme at the Free University, Berlin, Germany during the Ph.D. programme; He was a Scholar to the German Academic Exchange Services (DAAD); and at various times, Junior Associate and Regular Associate of the Abdus Salam International Centre for Theoretical Physics, Trieste (ICTP), Italy; and he was a Royal Society of London International Incoming Visitor in 2007 at The School of Physics and Astronomy, University of Edinburgh, Edinburgh, Scotland. He has participated in scientific activities of the ICTP at various levels from 1997 till date, among others.