[1] Stanford Univ, Stanford Inst Mat & Energy Sci, Stanford, CA 94305 USA
[2] Stanford Univ, Dept Chem Engn, Stanford, CA 94305 USA
[3] Adv Light Source, Berkeley, CA 94720 USA
[4] Swiss Fed Inst Technol, Solid State Phys Lab, CH-8093 Zurich, Switzerland