As a young graduate recently recruited by EDF’s R&D division, her thesis Small high-efficiency solar cells based on chalcopyrite Cu(In,Ga)Se2 materials won her the Science Award in the first R&D Awards of 2013. She is living proof that value can't be measured in years. We went to meet her.
What is the focus of your research?
Since I completed my thesis, I've worked essentially on solar microcells, which is all about designing an innovative cell architecture that saves materials while also exploiting the full potential of solar concentration for energy generation. In practical terms, we have been able to demonstrate that it is possible to design – and more importantly manufacture – CIGS1 cells measuring just 50 microns across that can support a solar concentration ratio of 500, whereas the current state-of-the-art is no higher than 15.
Ultimately, this means that the efficiency of our cells will increase from 16% to 21%, which is a very significant advance.
So what is the scientific barrier that you have crossed?
Basically, the idea is simple, namely to miniaturise solar cells instead of using conventional size cells when using concentrated sunlight. This concept opens up 2 opportunities: firstly, a significant reduction of resistance losses, and secondly, material costs reduction. It then becomes possible to 'print' cells precisely in the location of each light concentration. In order to put the idea into practice, we also had to measure its effects using modelling and simulation techniques, and then verify those outcomes in lab-scale experimentation. We've been able to successfully complete both stages!
Personally, I need my research work – however upstream it might be – to become a real product someday. And it would be even better if it were in a field that is still virgin territory! I am therefore very proud of the patents derived from our research works.
So what is your next challenge?
There are several, actually. We first have to confirm our results using a slightly more statistical approach: producing multiple cells and characterising them to check their average performance and the basis for optimising their overall performance. Miniaturisation, of course, complicates everything: for example, we have to invent sufficiently accurate production methods, since cell geometry has a considerable impacton their performance.
Then we still have to find the optimum balance between the shape of the cell (ideally the smallest possible) and the economic equation, which includes manufacture costs and usage (and therefore its market) of the end product.
What is your personal vision of research?
I think that since technologies are now evolving very quickly, collaborative work is vital nowadays: for our in-house teams, of course, but also by hosting PhD students (we currently have 17 doctoral theses underway in the lab!) and pooling the resources of multiple stakeholders.
Research engineer at EDF’s R&D division. New Photovoltaic Concepts Project Manager, coordination of solar micro-cells and head of photolithography.
Teaching of doctoral students.
Postgraduate studies at the French Institute for Photovoltaic Energy Research & Development (IRDEP), a mixed (EDF’s R&D divison/CNRS/Chimie ParisTech) research facility working on thin-layer Cu(In,Ga)Se2 solar microcells for use in light concentration generating technologies,
École Polytechnique and Masters 2 at the Université Pierre et Marie Curie specialising in Materials Science and Nano-Objects as part of the Thin-layer & Active Surfaces programme.