Recent talks

2015

• Dynamics of formation and electrical transport in molecular junctions
  Calame, Michel.

  (2015) .

• Does molecular electronics compute ?
  Calame, Michel.

  (2015) .

• Molecular junctions: dynamics of formation and electrical transport
  Calame, Michel.

  (2015) .

• Molecular junctions: dynamics of formation and electrical transport
  Calame, Michel.

  (2015) .

• Formation Mechanisms and Electrical Transport: from Individual to Arrays of Molecular Junctions
  Calame, Michel.

  (2015) .

• From transport mechanisms in molecular junctions to ion sensing using ISFETs
  Calame, Michel.

  (2015) .

2014

• Electromechanical structure of molecular junctions & alternative contacting strategies
  Calame, Michel.

  (2014) .

• Formation and transport mechanisms in individual and self-assembled networks of molecular junctions
  Calame, Michel.

  (2014) .

• Mechanical and electronic structure of molecular junctions and alternative contacting strategies
  Calame, Michel.

  (2014) .
  [Abstract]

  The formation of molecular junctions (MJs) is a dynamic process [1] where the atomic details of the interface between the contact electrodes and the molecule(s) strongly influence its electronic properties. The variability of possible microscopic configurations and limited stability of the different arrangements make a detailed understanding of MJs delicate and limit their applicability as electronic and optoelectronic compounds [2]. Time-dependent and spectroscopic characterizations of these systems can thus help developing a deeper insight in the mechanisms at stake. With a Conducting Atomic Force Microscope (C-AFM), we have simultaneously investigated the electrical and mechanical properties of Au-Au and Au-molecule-Au junctions [3]. We show that scatter plots (2D histograms) are a powerful method to correlate force with conductance. Our measurements support a scenario where, in about twenty percent of the MJs formed during a breaking cycle, the molecules migrate along the metal contacts thanks to the mobility of surface atoms. Using a mechanically-controllable break junction (MCBJ) setup operated in a liquid environment, we have recorded IV characteristics and observed current rectification effects in symmetric and asymmetric molecular junctions. From a simple analytical model, we can extract basic parameters such as the electronic coupling provided by different anchor groups. The relatively fast IV acquisition rate achieved opens the possibility to follow the evolution and symmetry changes of IV traces along a single conductance plateau. We also investigated the effect of dipolar binding groups on the formation of conductance plateaus not only during opening cycles (i.e. opening and breaking of the junction) but also during closing cycles (i.e. while pushing the contacts together). An alternative approach to contact few molecules consists in using graphene electrodes. Gold, the most commonly used metal to create MJs, presents major drawbacks such as high mobility of the surface atoms, a strong screening of a backgate potential and the existence of many possible binding geometries leading to ill-defined MJ conductances. Graphene is interesting in this context as its planarity will grant an easier access for gating experiments as well as facilitate optical and scanning probe imaging. Furthermore, it can be produced at large scale through e.g. chemical vapor deposition (CVD). Using an electroburning process, we have recently demonstrated the fabrication of nanoscale gaps in graphene constrictions at high yield [4]. The electrodes formed in this way are suitable for the subsequent contacting of molecules. References 1. J. Brunner et al., Random telegraph signals in molecular junctions, submitted to J. Phys. Cond. Matt. (2014) 2. See e.g. the special issue: Does molecular electronics compute? Nat. Nanotech 8, 377 (2013); See also the review: Molecular electronics: functions and features arising from tailor-made molecules, M. Mayor, M. Calame and R. Waser, in Nanoelectronics and information technology, 3rd Ed., Wiley-VCH (2012) 3. C. Nef et al., Force-conductance correlation in individual molecular junctions, Nanotechnology, 23, 365201 (2012) 4. C. Nef, et al., High-yield fabrication of nm-size gaps in monolayer CVD graphene, Nanoscale 6, 7249 (2014)

• Emerging functionality in nanoparticles arrays
  Calame, Michel.

  (2014) .
  [Abstract]

  Arrays of metal nanoparticles interlinked by an organic matrix have attracted a lot of interest due to their diverse electronic and optoelectronic properties [1]. By controlling the nature of the matrix material and the interparticle distance, the electronic behavior of the nanoparticle array can be substantially tuned and controlled [1,2]. We have recently shown that nanoparticle arrays form a useful architecture to build networks of molecular junctions. Here, the nanoparticles act as electronic contacts to the molecules and a molecular functionality can be used to induce an overall functionality at the array scale. Using this approach, we have build nanoarticles arrays exhibiting for instance redox [3] and optical [4] switching behaviors. The later is made possible thanks to the excitation of surface plasmons in the nanoparticles. Thanks to this particular configuration, the molecules can easily be accessed by optical means. A resonant excitation of the molecules within the array will thus leads to a photoconductance enhancement at the array level [5]. Nanoparticle arrays thus represent an interesting architecture opening possibilities for the development of novel molecular scale electronic and optoelectronic devices. Their possible implementation as an information storage platform or even as computing networks thanks to a defect-tolerant architecture is currently under investigation [6]. References 1. M.A. Mangold et al., Nanoparticles arrays, to appear in the Springer Handbook of Nanoparticles (2014). 2. M. Calame, Molecular junctions: from tunneling to function, Chimia Int. J. Chem, 64 (6), 391-397 (2010). 3. J. Liao et al., Cyclic conductance switching in networks of redox-active molecular junctions, Nano Letters, 10 (3) , 759–764 (2010). 4. S. van der Molen et al., Light-controlled conductance switching of ordered metalmolecule- metal devices, Nano Letters, 9 , 76-80 (2009). 5. M. A. Mangold et al., Resonant Photoconductance of Molecular Junctions Formed in Gold Nanoparticle Arrays, J. Am. Chem. Soc., 133 (31) , 12185–12191 (2011). 6. G. Wendin et al., Synaptic Molecular Networks for Bio-Inspired Information Processing, Int. J. Unconv. Comp., 8 , 325-332 (2012).

• Silicon nanowire bio-chemical sensors
  Calame, Michel.

  (2014) .

2013

• Spectroscopic insight on electrical transport through molecular junctions
  Calame, Michel.

  (2013) .

• Characterizing the electronic and mechanical structure of molecular junctions
  Calame, Michel.

  (2013) .

• Electronic transport in molecular junctions and junctions networks
  Calame, Michel.

  (2013) .
  [Abstract]

  Electronic transport in molecular junctions and junctions networks Michel Calame Department of Physics and Swiss Nanoscience Institute, University of Basel, Switzerland Nanometer scale structures embedding molecular compounds represent a versatile test-bed to investigate non-equilibrium quantum transport phenomena. We follow two experimental routes to characterize and control electronic transport in molecular junctions. Using atomic contacts prepared with a mechanically-controllable break junction system, we investigate the electro-mechanical properties of individual molecular junctions. Operating these devices in a liquid environment, we have for instance observed the importance of intermolecular interactions and pi-pi stacking effects [1]. Molecular junctions are not static devices and undergo dynamical reconfigurations. By acquiring IV characteristics at a relatively high rate, we can follow the time evolution of the junctions and gain insight in the various geometries explored and their electronic properties. Conducting AFM further provides the possibility to simultaneously investigate the electrical and mechanical properties of Au-Au and Au-molecule-Au junctions [2]. Using Au nanoparticle arrays as a backbone structure, we investigate the transport properties of molecular junctions networks. We have demonstrated that this platform can be efficiently used to study transport modulation effects via chemical [3] and optical [4] stimuli as well as study photoconductance effects [5]. 1. S. Wu et al., Nature Nano., 3, 569-574 (2008) 2. C. Nef et al., Nanotechnology, 23, 365201 (2012) 3. J. Liao, et al., Nano Letters, 10 (3), 759–764 (2010) 4. S. van der Molen, et al., Nano Letters, 9 , 76-80 (2009) 5. M. A. Mangold et al., ACS Nano, 6 (5) , 4181–4189 (2012)

2012

• Characterizing the mechanisms governing electrical transport in molecular junctions
  Calame, Michel.

  (2012) .

• Chemosensing with Si nanowire field-effect transistors
  Calame, Michel.

  (2012) .

• Insights into the electronic and mechanical structure of molecular junctions
  Calame, Michel.

  (2012) .

• Electrical transport in molecular junctions: spectroscopy and switching behavior
  Calame, Michel.

  (2012) .

• Insights into the electronic and mechanical structure of molecular junctions
  Calame, Michel.

  (2012) .

• Discussion moderation on ‘Exploiting inherent quantum effects at room temperature in single molecule junctions’
  Calame, Michel.

  (2012) .

2011

• Molecular junctions and devices: from tunneling to function
  Calame, Michel.

  (2011) .

• Dual-gated Si (nano)wire FETs for ion- and bio-sensing
  Calame, Michel.

  (2011) .

• Dual-gated Si nanowire FETs for ion- and bio-sensing
  Calame, Michel.

  (2011) .

• Well ordered Au nanoparticles arrays: a template structure for molecular-scale electronics
  Calame, Michel.

  (2011) .

• Nanoelektronik: Reise in der Nanowelt
  Calame, Michel.

  (2011) .

2010

• Switching functionality in molecular junctions networks
  Calame, Michel.

  (2010) .

• Few molecules junctions: formation mechanisms, transport and spectroscopy
  Calame, Michel.

  (2010) .

• Few molecules junctions: formation mechanisms, transport and spectroscopy
  Calame, Michel.

  (2010) .

• Formation mechanisms and functionality in molecular junctions
  Calame, Michel.

  (2010) .

• Voyage au coeur de la matière: nanosciences et nanotechnologie
  Calame, Michel.

  (2010) .

• Unraveling the formation mechanisms and functionality in molecular junctions
  Calame, Michel.

  (2010) .

• A glimpse into the world of nano- and molecular electronics
  Calame, Michel.

  (2010) .

• Formation mechanisms and functionality in molecular junctions
  Calame, Michel.

  (2010) .

• Networks of molecular junctions
  Calame, Michel.

  (2010) .

• Voyage au coeur des nanosciences
  Calame, Michel.

  (2010) .

• Electrically and mechanically controlled nanogaps for molecular electronics
  Calame, Michel.

  (2010) .

2009

• Formation mechanisms and functionality in molecular junctions
  Calame, Michel.

  (2009) .

• Hybrid organic-inorganic devices: electrical functionality and sensing at the molecular level
  Calame, Michel.

  (2009) .

• Formation mechanisms and functionality in molecular junctions
  Calame, Michel.

  (2009) .

• Individual molecular junctions
  Calame, Michel.

  (2009) .

• Formation mechanisms and functionality in molecular junctions
  Calame, Michel.

  (2009) .

• Molecular junctions: Formation mechanisms and functionality
  M.Calame.

  (2009) .

• Molecular electronic junctions
  Calame, Michel.

  (2009) .

2008

• Electronics with single molecules: vision or reality?
  Calame, Michel.

  (2008) .

• Molecular electronic junctions with function
  Calame, Michel.

  (2008) .

• Molecular electronics junctions with function
  Calame, Michel.

  (2008) .

• Soft electronic junctions: from single molecules to networks
  Calame, Michel.

  (2008) .

• Molecular electronics junctions with function
  Calame, Michel.

  (2008) .

• Soft electronic junctions: from single molecules to networks
  Calame, Michel.

  (2008) .

• Le monde de la nanoélectronique: des fils de Silicium aux molécules
  Calame, Michel.

  (2008) .

• IsNanoSens: Integrateable Si Nanowire Sensing platform
  Calame, Michel.

  (2008) .

2007

• Versatile molecular junction networks from colloid arrays
  M.Calame J. Liao, Bernard Molen Mangold Schönenberger L. . S. J. . M. . C..

  (2007) .

• From individual molecular junctions to networks
  Calame, Michel.

  (2007) .

2006

• From single molecule contacting to networks of molecular junctions
  Calame, Michel.

  (2006) .

• Molecular electronics: From single junctions to networks
  Calame, Michel.

  (2006) .

• Twenty years of two-coils technique: Piero’s eyes into superconducting phenomena
  Calame, Michel.

  (2006) .

• From single molecule devices to networks of molecular junctions: Parts I & II
  Calame, Michel.

  (2006) .

• Paving the road for single molecule electronics
  Calame, Michel.

  (2006) .

• From single molecules junctions to networks of molecular junctions
  Calame, Michel.

  (2006) .

2005

• Molecular junctions: from single molecules to networks
  Calame, Michel.

  (2005) .

• Electronic properties of C60 molecular junctions in liquid
  Calame, Michel.

  (2005) .

2004

• Break junctions and nanogaps for molecular electronics
  M.Calame.

  (2004) .

• Carbon nanotubes: next generation biosensors ?
  M.Calame.

  (2004) .

• Electrical characterisation of DNA molecules
  M.Calame.

  (2004) .

• Single molecule manipulation and characterisation using nanoscale devices
  M.Calame.

  (2004) .