1 Supporting Information Two-Dimensional Gold Quantum Dots with Tunable Bandgaps Shiva Bhandari 1 , Boyi Hao 1 , Kevin Waters 1 , Chee Huei Lee 1 , Juan-Carlos Idrobo 2 , Dongyan Zhang 1 , Ravindra Pandey 1 , Yoke Khin Yap 1 * 1 Department of Physics, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA. 2 Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 3783, USA.