11th Early Stage Researchers Workshop in Nanoscience

Title: Remotely controlled colloidal nanosystems

Abstract: 

Our research is focused on the development of multifunctional nanomaterials for applications in biology and medicine. We design, synthesize and customize nano- and micro-materials with applications in therapy, diagnostics, and imaging.
The interaction of light or alternating magnetic fields with inorganic NPs is orders of magnitude stronger than with organic molecules, in particular, due to their larger absorption cross-sections. Therefore inorganic NPs (or hybrid composites) offer a convenient platform to produce remotely controlled colloidal nanosystems. These interactions can be applied to develop nanoheaters, nanoreactors, or to induce a controlled drug release that will offer novel and personalized tools for therapy and imaging.

Biography: 

Dr. Beatriz Pelaz is the director of the BioNanoTools Lab (https://bntsite.wordpress.com/), ERC grantee (Starting grant 2020), and Principal Researcher at the CiQUS. She graduated in Chemistry from University of Valladolid (2005) and Biochemistry from University of Zaragoza (UZ, 2011). She obtained a Master degree in experimental organometallic chemistry from the University of Valladolid (2006), to later carry out PhD studies at de la Fuente’s lab at the Institute of Nanoscience of Aragon (UZ) (2007-2012). She was a postdoctoral researcher (2012-2013) and a Humboldt Fellow (2014-2015) at Parak’s lab (Philipps-University of Marburg). In 2016, she moved to the CiQUS@USC with a JIN/RETOS-project. She was awarded with a Ramon y Cajal contract (ranked 3rd in the Chemistry panel, 2017 call).

Title: Real-space visualization of excitonic states in single molecules

Abstract: 

The ability to control the emission from single-molecule quantum emitters is an important step towards their implementation in optoelectronic technology. [1] Even though excitonic states in single molecules can be detected by far-field spectroscopies, access to the individual modes in real space will bring the much needed insight into the photophysics of these fascinating quantum phenomena. Here I will show combined tip-enhanced spectromicroscopy with scanning tunneling and atomic force microscopies to inspect exciton states of molecular emitters engineered on surfaces. I will introduce electroluminescence from phthalocyanine-derived metal complexes on thin insulating layers. [2] Copper phthalocyanine (CuPc) emission can be reproducibly switched by atomic scale manipulations permitting precise positioning of the molecule on the NaCl ionic crystal lattice. I will show the modulation of electronic and optical bandgaps, and the exciton binding energy in CuPc by tens of meV and explain this effect by spatially-dependent Coulomb interaction occurring at the molecule-insulator interface. [3] Zinc phthalocyanine (ZnPc) shows emission from neutral and charged excitons (trions). I will present the intertwined exciton-trion dynamics combining radio frequency modulated scanning tunnelling luminescence with time-resolved single photon detection. [4] At last, PTCDA forms coupled molecular assemblies with entangled excitonic states.  I will present hyperspectral mapping of the eigenstates and the comparison with calculated many-body optical transitions. [5]  

These results reveal the possibility of tailoring excitonic properties of organic dye adsorbates for advanced functionalities and establish the methodology to address them individually at the nanoscale.

References

[1] K. Kuhnke et al., Chemical Reviews, 117 5174 (2017).

[2] J. Doležal et al., Nano Letters, 19, 8606 (2019).

[3] J. Doležal et al., ACS Nano, 14, 8931 (2020).

[4] J. Doležal et al. ACS Nano 15, 7694 (2021)

[5] J. Doležal et al. arXiv: 2110.00310v1 (2021)

 Biography: 

I am currently a Ramon y Cajal Fellow at the Institute for Material Science of Madrid (ICMM-CSIC), where I conduct my research on structural, electronic and optical characterization of low-dimensional carbon-materials. Previously I have been researcher of the ERC Synergy project Nanocosmos at the ICMM-CSIC and Humboldt Research Fellow in the Max Planck Institute for Solid State Research. I performed my PhD in the Center for Astrobiology (Spain) associated to NASA Astrobiology Institute. My investigations lie at the horizon where the fields of surface science, astrophysics and nanophotonics meet, yet I am further interested in any problem where carbon physics and chemistry dominate.