Neil Greenham is Professor of Physics at the Cavendish Laboratory, University of Cambridge.  His research focuses on novel low-dimensional semiconductors that can be deposited from solution, in particular conjugated polymers and semiconductor nanoparticles.  He made important early advances in the development of polymer light-emitting diodes, improving efficiencies and understanding the physics of device operation.  He was a Miller Fellow at the University of California, Berkeley from 1995-96, where he developed the first solar cells based on blends of polymers with inorganic semiconductor nanocrystals.  His research now focuses on photovoltaics, using device measurements, spectroscopy, advanced imaging techniques and modelling to understand and control loss mechanisms, and developing new materials to break the conventional limits on solar cell efficiency. He was awarded the Royal Society Kavli Medal and Lecture in 2013.