The Solar Energy Research Group of the Department of Physics at the University of Pretoria is dedicated to conducting globally competitive, cutting-edge research in the area of thin film photovoltaics.
With increasing worldwide demand for renewable energy in mind, our mission is to improve existing thin film technologies as well as develop new photovoltaic materials from more earth abundant resources in order to fabricate highly efficient, low cost solar cells.
Our ability to complete each step of the device fabrication process; from substrate preparation, synthesis of nanoparticles absorber film coating and sintering, additional film and metallic grid deposition, and device characterization – within our own lab allows us to study all aspects of device performance and affords unique insight into the fundamental science behind each contributing factor.
Our collaborations with esteemed groups both in the South Africa, Continental and overseas provide opportunities to exploit highly sophisticated procedural and characterization methods in an interdisciplinary environment. Our graduate researchers benefit from international training and workshops designed to position them as leaders who will shape the future of the global solar economy.
Research Associates
Dr Augusto Machatine (Group Theory and Optical Measurements)
PhD students
- Fredjoe Nambala
- Kelebogile Maabong
- Joseph Simfukwe
- Benard Mwankemwa
MSc students
- Sebastien Mienie
- Sipho Congolo
- Abrie Cronje
- Kyle Venter
1. Hybrid organic/inorganic solar cell
Development of high efficiency multi-junction organic solar cells using state-of-the-art techniques to fabricate novel Hybrid inorganic/organic solar cells on silicon. Hole conducting polymers like PEDOT:PSS, Perovskites and small molecule organic semiconductors are used on Si to produce HIOSC. In addition, detailed characterisation and analysis of the materials and devices using a wide range of structural, electronic, electrical and optical techniques is done.
2. Thin film solar cells
Solar cells based on CuZnSnSe2 absorbers show growing efficiencies and performance among all thin-film technologies. This is a kind of thin film material for solar cells used to replace CuInGaSe due to decrease in availability of In and Ga. Main research topics include band gap and interface engineering of the CZTS absorber in order to find the optimum tradeoff between highest device efficiency and cost-effective mass production, development of processes for other constituent layers and multijunction (tandem) solar cells.
3. Biohybrid solar cells
The aim of this project will be to construct a novel Biohybrid "green" bio-photo-electrode with significant potential to outperform presently available electrode prototypes for photo-conversion and hydrogen production from water-splitting. Work is focused on nano-engineering of extremely stable natural photosynthetic complexes in order to specifically attach them to the electrodes obtained using hematite. Hematite is a cheap earth abundant semiconductor material with bandgap suitable for solar energy conversion. The performance of such a Biohybrid device will be further improved by adding metallic nanoparticles in order to selectively enhance absorption of the light-harvesting complexes, and, as a result, increase the product output of photo-conversion.
4. Nanostructures materials
The overall goal of this project is to develop plasmonic nanostructures using combined bottom-up self-assembly processes and standard top-down processes. Simple experimental techniques are available with different e-beam deposition techniques, including state-of-the-art Molecular Beam Epitaxy. The nanostructures will be used to enhance light harvesting in solar cell.
Infrastructure
- Deposition techniques: Electron Beam Deposition, Molecular Beam Epitaxy, Sputtering Deposition Technique, Laser Spray Pyrolysis, Spin Coater, Dip Coater.
- Electrical Characterization: Deep Level transient Spectroscopy (DLTS) and Laplace DLTS, Current-Voltage-Temperature (IVT) Measurements, Admittance Spectroscopy, Hall Measurements, Four Point Probe, Solar simulator, Electrochemical Impedance Spectroscopy.
- Surface Characterization: Atomic Force Microscopy, Scanning Tunnelling Microscopy, High Resolution Transmission Electron Microscopy, High Resolution Scanning Electron Microscopy.
- Structural Characterization: X-Ray Diffraction Photoluminescence, X-Ray Photoelectron Spectroscopy, Raman Spectroscopy, Infra-Red Spectroscopy, UV-Vis Ellipsometer.
- Synchrotron Radiation Facility: South Africa participates in the European Synchrotron Facility at Grenoble. We have available beam line at Lawrence Berkeley Synchrotron Facility in USA.
- Optical Characterization: Raman Spectroscopy, Ultrafast Pump Probe Spectroscopy.
Departmental Collaboration
- Dr Tjaart Kruger in Biophysics
University Collaboration
- Prof Egmont Rohwer in Chemistry
National Collaboration
- Dr Eric Maluta, University of Venda
- Dr Bonnex Mwakikunga, Council for Scientific and Industrial Research
- Dr Mandla Msimanga, Tshwane University of Technology
African Continent Collaboration
- Dr Onesmus Munyati, University of Zambia, Lusaka, Zambia
- Dr Margaret Samiji, University of Dar es Salaam, Dar- es Salaam, Tanzania
International Collaboration
- Prof FCC Ling, Hong Kong University, Hong Kong, China
- Prof David Cahen, Weizmann Institute of Science, Rehovot, Israel
- Dr Artur Braun, Empa, Zurich, Switzerland
- Prof Raoul Frese, Vrye Universiteit of Amsterdam, Amsterdam, Netherlands
1. M Diale, AS Erickson, D Cahen, 1st Africa PV conference, March 2014 proceedings
2. A Braun, M Diale, T Huthwelker, J van Bokhoven, Synchroton Radiation News, Meeting Reports 29(1) (2016) 13
3. AT Paradzah, FD Auret, MJ Legodi, E Omotoso, M Diale, Nuclear Instruments and Methods in Physics Research B 358 (2015) 11116
4. K Maabong, Y Hu, A Braun, AGJ Machatine, M Diale, Journal of Materials Research, (2016) 1
5. SM Tunhuma, FD Auret, MJ Legodi, M Diale, Journal of Applied Physics, 119 (2016) 145705
Contact
Prof Mmantsae Moche Diale
Solar Energy Research Group
Department of Physics
University of Pretoria
Tel: +27 12 420 4418
Email:[email protected]