Highly efficient perovskite solar cells based on a nanostructured WO 3 –TiO 2 core–shell electron transporting material

A novel core–shell nanostructured WO 3 is investigated in detail and shown to work successfully as an electron transporting material in hybrid perovskite solar cells. A thin TiO 2 shell reduces charge recombination while highly textured single-crystal WO 3 nanostructures promote fast electron transport leading to an efficiency above 11%.