  Organic Solid-Solid Wetting Deposition (OSWD) enables the fabrication of
supramolecular architectures without the need for solubility or vacuum
conditions. The technique is based on a process which directly generates
two-dimensional monolayers from three-dimensional solid organic powders.
Consequently, insoluble organic pigments and semiconductors can be made to
induce monolayer self-assembly on substrate surfaces, such as graphene and
carbon nanotubes, under ambient conditions. The above factuality hence opens up
the potential of the OSWD for bandgap engineering applications within the
context of carbon based nanoelectronics. However, the doping of graphene via
OSWD has not yet been verified, primarily owing to the fact that the classical
OSWD preparation procedures do not allow for the analysis via Raman
spectroscopy, one of the main techniques to determine graphene doping. Hence,
here we describe a novel approach to induce OSWD on graphene leading to samples
suitable for Raman spectroscopy. The analysis reveals peak shifts within the
Raman spectrum of graphene, which are characteristics for p-type doping.
Additional evidence for chemical doping is found via Scanning Tunneling
Spectroscopy. The results open up a very easily applicable, low-cost, and
eco-friendly way for doping graphene via commercially available organic
pigments.
