Publications by Ravi Shankar Sundaram

Self-Assembled Electrical Biodetector Based on Reduced Graphene Oxide

Klaus Kern, Kannan Balasubramanian, Ravi Shankar Sundaram, Subramanian Sundaram

Large-scale fabrication of graphene-based devices is an aspect of great importance for various applications including chemical and biological sensing. Toward this goal, we present here a novel chemical route for the site-specific realization of devices bas ...

2012

Electrical Properties of Chemically Derived Graphene

Ravi Shankar Sundaram

Graphene, an atomically thin sheet of carbon, is the most recent endeavor for the application of carbon nanostructures in conventional electronics. The envisioned creation of devices completely carved out of graphene could lead to the revolution of electro ...

EPFL2011

The Graphene-Gold Interface and Its Implications for Nanoelectronics

Klaus Kern, Marko Burghard, Ravi Shankar Sundaram

We combine optical microspectroscopy and electronic measurements to study how gold deposition affects the physical properties of graphene. We find that the electronic structure, the electron-phonon coupling, and the doping level in gold-plated graphene are ...

American Chemical Society (ACS)2011

Electronic properties and atomic structure of graphene oxide membranes

Klaus Kern, Daniela Pacilè, Marko Burghard, Ravi Shankar Sundaram

We have performed a near-edge X-ray absorption fine-structure (NEXAFS) and a transmission electron microscopy (TEM) investigation of freely suspended graphene oxide (GO) sheets. We utilized a photoemission electron microscope to identify GO membranes and t ...

2011

Atomic Structure of Reduced Graphene Oxide

Klaus Kern, Marko Burghard, Ravi Shankar Sundaram

Using high resolution transmission electron microscopy. we identify the specific atomic scale features in chemically derived graphene monolayers that originate from the oxidation-reduction treatment of graphene. The layers are found to comprise defect-free ...

American Chemical Society (ACS)2010

Electrical Conduction Mechanism in Chemically Derived Graphene Monolayers

Klaus Kern, Marko Burghard, Ravi Shankar Sundaram

We have performed a detailed study of the intrinsic electrical conduction process in individual monolayers of chemically reduced graphene oxide down to a temperature of 2 K. The observed conductance can be consistently interpreted in the framework of two-d ...

American Chemical Society (ACS)2009

Noninvasive metal contacts in chemically derived graphene devices

Klaus Kern, Marko Burghard, Eduardo Jian Hua Lee, Ravi Shankar Sundaram

We study the properties of gold contacts on chemically derived graphene devices by scanning photocurrent microscopy and gate-dependent electrical transport measurements. In the as-fabricated devices, negligible potential barriers are found at the gold/grap ...

AIP American Institute of Physics2009

Chemical Vapor Deposition Repair of Graphene Oxide: A Route to Highly Conductive Graphene Monolayers

Klaus Kern, Marko Burghard, Ravi Shankar Sundaram

Highly conductive chemically derived graphene can be synthesized using an efficient two-step method starting from graphene oxide. The key strategy involves the use of a CVD process to heal defects contained within the monolayers, which imparts a two order ...

Wiley2009

Electrochemical modification of graphene

Klaus Kern, Kannan Balasubramanian, Marko Burghard, Ravi Shankar Sundaram

Nanoparticles on an atomic carpet: Individual graphene sheets have been decorated with metal nanoparticles through electrochemistry. The attachment of Pd particles onto graphene renders it sensitive to hydrogen. The controlled functionalization of graphene ...

Wiley2008

Uniformly Dispersed Deposition of Colloidal Nanoparticles and Nanowires by Boiling

László Forró, Andrzej Kulik, Gerit Kulik, Jürgen Brugger, Jin Won Seo, Sylvia Jeney, Arnaud Magrez, Kyumin Lee, Martial Duchamp, Ravi Shankar Sundaram

Uniformly dispersed deposition of various nanoparticles (gold and silver of 20?50 nm) and nanowires (ZnO and VOx) on different surfaces (Si, GaAs, mica, and steel) was obtained by boiling colloid drops on preheated substrates. Our results suggest a deposit ...

AIP American Institute of Physics2007