One atom thick, 2-dimensional, free-standing goldene sheets

2D materials have demonstrated an immense interest in research community due to their wide range of applications in photovoltaics, optical sensing, drug delivery etc. Gold nanostructures have synthesized by various biological, photochemical and wet chemical routes but the reports on the synthesis of 2D gold are not available. For the first time, we report a technique to synthesize one-atom thick, free-standing, 2D gold crystals (i.e. goldene, we named it  analogous to graphene) and periodic array of goldene. [1] Thin films of gold were deposited via thermal evaporation process on highly polished single crystalline (c-axis orientation) sapphire wafer. These films were post heat treated to 475^oC. Transmission electron miscriscpiy imaging of these surface features demonstrated herringbone and honeycomb lattices of gold due to surface reconstraction. HRTEM imaging of surface only features showed a lattice spacing of 2.4Å. Selective aera electron diffraction (SAED) pattern showed the presence of (11?1), (200) and (220) planes of fcc gold. Our extensive AFM imaging of goldene films confirmed that they are one-atom thick (~2Å) gold crystals. EDS, XPS and STEM confirmed the chemical identity of these 2D one atom thick goldene crystals that they are made up of gold only.[2]  Goldene showed a semiconductor response with a knee voltage of ∼3.2 V, and I/V spectroscopy revealed periodic room temperature Coulomb blockade oscillations. Goldene exhibited multiple, intense and well-resolved optical absorption peaks across the UV-vis region with optical band gap of 3.59 eV.

Sudhir Sharma obtained masters received PhD degree from Indian Institute of Science Bangalore, India in 2012. As post doc fellow, he joined at Centre for Nanoscience and Engineering, IISc. Bangalore, India. In November 2013, Dr. Sharma moved to NYU Abu Dhabi UAE as a research associate. Currently, he is working as Senior Research Scientist at NYU Abu Dhabi. His publication record includes about 60 publications in international journals and more than 100 presentations in international conferences. His research interest includes advancement in quantum material synthesis and their applications.