The way materials are assembled within devices decisively determines their function. In silicon solar cells, for example, the sandwich structure around the single crystalline silicon photoactive layer has been optimised over more the 50 years. Alternative strategies employing partially disordered materials are interesting because they have the potential to reduce the cost and energy input in solar cell manufacture. The first part of my presentation will sketch the evolution of perovskite solar cells from dye sensitised solar cells, highlight current developments and outstanding challenges. I will also briefly discuss the use of these unusual semiconductors for applications beyond photovoltaics.

The second part focusses on an equally important component of a sustainable energy technology, lithium ion batteries. While this is intrinsically a sub-discipline of electrochemistry, materials science and -physics can play an important role in optimising proven electrochemical systems. After introducing some basic battery concepts, I will focus on morphological aspects that play a role in battery operation and how their optimisation improve battery performance, encompassing electrodes, electrolytes, and time permitting separators.