Michael Grätzel (born 11 May 1944, in Dorfchemnitz, Saxony, Germany)[4] is a professor at the École Polytechnique Fédérale de Lausanne where he directs the Laboratory of Photonics and Interfaces. He pioneered research on energy and electron transfer reactions in mesoscopic-materials and their optoelectronic applications. He co-invented with Brian O'Regan the Grätzel cell in 1988 and pioneered the use of nanomaterials in lithium ion batteries.[2][5][6][7]