Mohamed Henini

Low dimensional semiconductor structures and devices. 

The study of what are now called low dimensional structures and Devices (LDSD) began in the late 1970's when sufficiently thin epitaxial layers were first produced following developments in the technology of epitaxial growth of semiconductors, mainly pioneered in industrial laboratories for device purposes. The LDSD could be considered as a new branch of condensed matter physics because of the large variety of possible structures and the changes in the physical processes. The LDSD are materials structures whose dimensions are comparable with interatomic distances in solids. The novel properties of such structures caused by quantum effects offer device engineers new design opportunities for tailor-made new generation electronic/optoelectronic/photovoltaic devices.

The Physics Committee of the Science and Engineering Research Council (SERC) (now called EPSRC) first considered a proposal to launch a major initiative in LDSD in 1982. After recognizing the importance of the subject which was an area of worldwide interest, a formal approval to launch the programme was given by the science board in October 1984. This enabled the establishment of the first state-of-the-art epitaxial growth and sample preparation centres throughout the UK. Eight advanced epitaxial growth machines were purchased under LDSD, and one of them (Molecular Bean Epitaxy) was installed in the School of Physics in 1986. I was hired as a postdoctoral researcher in September 1986 and this position provided me a great opportunity to enter an exciting new field.

These activities include: (i) Mentoring my PhD students (currently supervising 6 International PhDs): 1-2-1 meetings; project meetings; giving feedback on paper drafts/conference talks/posters/theses; monitoring equipment) (ii) Driving research: reading papers; planning projects; meetings with collaborators to exchange research ideas; managing laboratories/funding/expenditures; writing presentations, attend research conferences. (i) Global Engagement: helping to develop the University Internationalisation agenda; international PhD student recruitment/Admissions, networking and profile raising, and building relations with international funding bodies; initiate MoU/MoA/NDA/Research Cooperation Agreement with international institutions. (ii) Services for wider research community: serve on program committees for conferences; serve on evaluation panels for funding agencies; serve on editorial board for journals; give keynote talks for conferences/workshops; write reference letters; host international visitors.

Research, which is an important component of our job, is all about discovering, learning new things, turning mistakes into learning experiences and sharing. I particularly enjoy interacting and collaborating with people from all around the world and from different backgrounds. It is amazing how scientific discoveries can cross borders in a world with so many different languages/cultures/customs. I entered academia because I enjoy working with students at all levels, doing research which is open-ended and derived from my own research interests and the trends in the research community/funding agencies. In this sense research in universities is very different from research in industry. 

Doing experimental research is not everybody's cup of tea. You have to endure long hours of work, have a lot of patience and be persistent and positive. In addition, research is challenging because one has to contribute with something new and prove it to the satisfaction of sceptical experts in your field who assess the validity, quality and originality of your academic work. Therefore, I have to develop feasible topics, look for a niche in which I can make a difference and determine what resources are available in terms of time, money and research team to support me. The Arabic proverb “one hand cannot clap” is one of my mottoes in life, meaning one has to work with others to achieve common goals. Hence, it is extremely important to build relationships with collaborators in order to access additional expertise and gain new perspectives on research. My international partnerships experience has enabled me to reach my goals and have a very successful scientific career.

I have several research projects running in parallel on low dimensional semiconductor structures which are based on III-V semiconductors, Oxides and Two-Dimensional Semiconductors. The main question is how to improve the structural/optical/electrical properties of these materials which are important for device applications that require for example high optical efficiency. We recently found that the presence of electrically active defects, in relatively high concentrations (≥1015 cm−3), hinders the figures of merit of the quantum dot intermediate band solar cells (QD-IBSCs). The question is what favours the nucleation of such defects and their role on the performance of QD-IBSCs.

The successful development of advanced materials of sufficient quality for devices requires the solution of several technological and engineering issues. The results of the various projects are expected to be applicable to the semiconductor community at large and contribute to the development of electronic/optoelectronic/photovoltaic devices. This research will also have an impact on the areas of nanoscience and nanotechnology. Furthermore, these projects will contribute to efficient training of young scientists and PhD students. Huge potentials are expected from these materials in both their quantum and thin-film forms in the areas of electronic/optoelectronic/photovoltaic devices technologies. The wide adoption of innovative materials and processes as well as the wide spectrum of different disciplines will allow the improvement of technical skills and the creation of new job careers.

I value the interaction with the students and the discussion of relevant research and course-related issues which kept the students interested in the subjects I taught. Through this experience, I have come to the conclusion that research-driven teaching is a valuable and positive beneficial motivation to the students' learning and education. I also firmly believe that the high standard of research I am carrying out has greatly improved and strengthened my teaching skills, which benefited the students in the MSc module course, tutorials, and laboratory classes. I enjoy teaching and consider it as complementary to my research work. For example, I initiated the teaching of the new subject area "Modern Applications of Physics: From Research to Industry " within my School. The aim was to help the students gain insights into how the application of Physics contributes to the advancements in technology.

Professor Leo Esaki, who was awarded the Nobel prize for physics in 1973, suggested the “five don’ts” rules at the LDSD conference which was chaired by myself in Cancun, Mexico in 2004: Don't allow yourself to be trapped by the constraints of your experience (If you allow yourself to get caught up in social conventions or circumstances, you will not notice the opportunity for a dramatic leap forward when it presents itself. Don't allow yourself to become overly attached to any authority in your field (the great professor, perhaps. By becoming closely involved with a great professor, you risk losing sight of yourself and forfeiting the free spirit of youth. Although the great professor may be awarded the Nobel Prize, it is unlikely that his subordinates will.) Don't hold on to what you don't need. Don't avoid confrontation (I myself became embroiled in some trouble with the company I was working for many years ago. At times, it is necessary to put yourself first and to defend your own position.) Don't forget your spirit of childhood curiosity (It is a vital component for imagination.) Having listed the five rules let me say that they alone will not create the conditions necessary for success. They are merely suggested guidelines. Good luck!