Technofile : Greased lightning

Silicon with microscopic pores emits visible light when struck by ultraviolet
rays or an electric current, making it a potential material for opto-electronic
devices. But the silicon is easily oxidised, making it useless for the job.
Purdue University researcher Jillian Buriak, however, has found that dunking the
silicon in a Lewis acid, such as aluminium chloride, creates a greasy protective
coating that prevents it from oxidising and doesn’t interfere with its ability
to transmit light.