Optical amplification of Eu3+ emission via energy transfer at molecular printboards for the efficiency enhancement of the solar cell

The main challenge in nanotechnology resides in the precise spatial (self-) organization of nanoscale components onto surfaces. The molecular printboards, monolayers of β-cyclodextrin (β-CD), can be employed to bind suitable guest molecules onto a surface with molecular accuracy based on the host-guest interactions. Several lanthanides and their organic complexes are known to exhibit photoluminescent properties. Based on this host-guest interaction, the first example of the controllable SAMs of Eu3+ complexes is prepared on the molecular printboards and is successful to demonstrate the stoichiometry of the efficient energy transfer pair with a close proximity proved by local image spectra and surface emission life-time. To further maximize the optical amplification, self-assembled organic/ nanoparticles multilayers based on multivalent supramolecular host-guest interactions between dendritic guest molecules and host-modified TiO2 particles can result in a strong absorption and efficient sensitization thin film. The stable positioning nanostructure is used as antireflecting layer for enhancing the solar cell UV conversion studied with the photo to current conversion efficiency.