Profile

My work

I’m investigating a new nanostructured type of silicon called ‘black silicon‘. It get its name because it looks, well… black. The surface is highly porous like a sponge, with tiny holes that make it excellent for trapping light. I’m trying to optimise the synthesis process and characteristics of my material to make it into a highly efficient anti-reflection coating for solar photovoltaic cells. By reducing the amount of wasted light reflected back, we can help make solar panels more energy efficient. If we can improve the efficiency of solar cells by only a tiny percentage, or bring down the manufacturing costs – the potential benefits are enormous.

I make my material using the FFC-Cambridge process, a revolutionary method for refining metal from its ores that was discovered by my boss a few years ago. This method uses molten salts, with involves working with high temperature furnaces – not too nice in the summer!

After the material has been made, we then characterize it using a whole palette of experimental techniques at out disposal. I’m very lucky that my department has one of the best electron microscope facilities in Europe which means I can look at the atomic makeup of the surfaces very clearly which helps understand how they form and how we can control the surface properties.

Gym before work (the new university sports centre is literally across the path from my dept’s new building, so there’s no excuse!) then check emails and plan the day’s work.

My black silicon is made by electrochemically removing the oxygen atoms from silicon crystal wafers using molten salts. This takes a lot of time. The salt I use is very moisture sensitive so needs a long drying procedure to remove all traces of water. Usually first thing in the lab I start drying a new batch of salt. After a day or so, it’s ready for use and ready to melt inside a crucible within a furnace at 850 degrees. Melting the salt also takes time, but luckily the electrochemical reduction with silicon is quite quick – only  a few minutes. If everything goes to plan, I can prepare about 10 black silicon wafers a week ready for structural characterization and optical and electronic testing with our collaborators in the Cavendish Laboratory in Physics.