1. Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, USA.
2. Department of Chemical Engineering, Columbia University, New York, NY 10027, USA.
3. National Light Source II, Brookhaven National Laboratory, Upton, NY 11973, USA.
4. Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA.