Organic Interfaces and Charge Transfer

This  research  line  aims  at  improving  our  knowledge  and  modeling  of  the  interfacial  properties  of  small  organic molecules at surfaces. The pivotal interest is  centered on organic semiconductors, but much atten- tion is also payed to the properties of the substrates  as well as to there functionalization. With the goal of  setting new directions for the fabrication/assembly of  high performance devices, we aim at a self consistent  description  and  tailoring  of  the dynamical  processes  of chemical interaction as well as charge transport at  interfaces. Starting from the basic study of the single  components, we follow the modification of the electronic  structure  at  hybrid  organic-inorganic  and  hetero-organic  junction,  which  are  representative  of  the  full  architecture of an archetypal device.  For a better control of the system degrees of freedom,  the substrate interaction is studied starting from single  crystal surfaces. The latter are eventually nanopatterned  and/or  functionalized  with  an  intermediate  self-assembled  monolayer  (alkanethiols,  aminoacid  derivatives) for specific linking to the substrate and suitable coupling to the next layer molecules.

Top: valence band resonant photoemission spectra  for  a  benzenediamine  molecule  adsorbed  on  Au (111) and Au(110), as shown in the 3D drawing on  the bottom. At variance with conventional ultraviolet  spectroscopy,  only  the  VB  states  localized  on  the  carbon  atoms  are  singled  out  when  the    photon  energy is tuned to the Carbon ionization threshold