Singlet fission for efficient solar cells

http://www.cam.ac.uk/research/news/two-for-one-in-solar-power

Singlet fission to split singlet excited electron into two triplet excited states.  Phenomenon seen in organic molecules at high concentrations (more molecular collisions).

"The team used a combination of laser experiments - which measure timings with extreme accuracy - with chemical methods used to study reaction mechanisms. This dual approach allowed the researchers to slow down fission and observe a key intermediate step never before seen."

Probably refers to the use of ultrafast spectroscopy to measure transient absorption and emission...