Inter College Lecture Series - Prof. Boateng Onwona‐Agyeman

Thursday, October 12, 2017 - 16:30
Centre for African Wetlands


Members of the University Community are hereby invited to the next Inter-College Lecture to be delivered by Prof. Boateng Onwona‐Agyeman (Department of Materials Science & Engineering).


TopicPreparations and Characterizations of Porous Structured Wide-band Gap Semiconductor Thin Films for Light-harvesting Application.

Date: Thursday, October 12th, 2017

Time: 4:30 pm

Venue: Centre for African Wetlands

Chairman: Prof. Daniel Asiedu, Provost, College of Basic and Applied

All are cordially invited.



Wide bandgap semiconductors have a lot of interesting practical applications in devices such as solar cells, light emitting diodes (LEDs), surface acoustic wave (SAW) etc. In the porous state, wide bandgap semiconductors usually have high specific surface area and pore volumes to accommodate other materials.  In the case of dye-sensitized solar cells for example, they are used as the photoelectrode and when coated with a thin layer of dye, can absorb photons from sunlight to start the process of converting sunlight to electricity. In this presentation, preparation and characterization of porous wide bandgap semiconductors such as titanium dioxide, zinc oxide and tin oxide and their role as important components in dye-sensitized solar cells will be discussed. Also, I will give brief description of the working mechanism of the spray pyrolysis deposition system and explain why it is very useful in preparing different porous structured wide bandgap semiconductors.

I would also describe certain metal-free organic complex dyes, their properties, advantages over metal-based organic complex dyes, their light harvesting capabilities and finally their combination with different porous wide bandgap semiconductors films in the construction of dye-sensitized solar cells. 




Prof. Boateng Onwona‐Agyeman obtained his BSc degree in Physics at the then University of Science & Technology (now KNUST) in Kumasi in 1994. He did his National Service at the Ghana Military Academy and Training Schools in Teshie, Accra as a civilian instructor.  After the National Service, he was employed as Assistant Scientific Officer at the Weights and Measures Division of then Ghana Standards Board.

 In 1997, he was awarded the Japanese Government Scholarship to study the MSc and Ph.D. degrees in Physics (Experimental Condensed Matter Physics) and Materials Science & Engineering respectively from 1997 to 2002 in Saga University, Japan. The postgraduate programme involved the preparation and characterization of doped and undoped triboluminescent semiconducting thin films for mechano-optical applications. This helped him to study the mechanism and operate wide range of vacuum-assisted thin film deposition instruments such as radio frequency (rf) magnetron sputtering, thermal evaporation, direct current sputtering etc.

After obtaining his PhD, he joined a semiconductor firm ENG Company in Japan for one year where he worked as a research engineer on the characterization of doped-silicon wafers used in large-scale integration (LSI) Technology, that is, the process of integrating or embedding thousands of transistors on a single semiconductor wafer.

He returned to academia from 2003 to 2005 as a post-doctoral fellow at the Faculty of Engineering, Shizuoka National University in Japan. During the postdoctoral programme, he did basic research on using cheaper deposition methods in preparing key components in solar cells such as transparent conducting thin films, porous semiconductors and metallic thin films as counter electrodes. In 2005, he joined a newly established Company, SPD Laboratory Inc. which was founded by his Professor (who retired in 2005) and this Company was supported by Shizuoka University (financially and also provided space for R&D work) as an incubator Company. This Company started the large-scale production of Spray Pyrolysis Deposition Systems to produce key components in dye-sensitized solar cells. The work involved transferring knowledge from the laboratory scale to commercialization and therefore the Company churned out patents from the different processing steps involved.

From 2007 to 2009, he was recruited to join a team of scientists and engineers to produce the first paper-based catalytic converters used in purifying exhaust gasses from small internal combustion engines. The second phase of the project involved the use of methane steam reformation process with different catalysts to produce hydrogen gas as fuel for fuel cells to power automobiles. The project was hosted by FCC Company and supported by Honda Company and the Japanese Government.

From 2009 to 2013, he was back with academia as Assistant Research Professor at Kyushu Institute of Technology and Kyushu National University, both public Universities in Japan. He joined the Department of Materials Science & Engineering, University of Ghana in 2013 as Senior Lecturer. His current research interest includes; transparent conducting thin film preparation/characterization, monitoring the photovoltaic performance of commercially installed solar cells, developing porous structured materials as diesel particulate filter (dpf), reforming natural gas into hydrogen and as filtrate in fuel cells. Currently, he is an Associate Professor and the Dean of School of Engineering Sciences.