PhD in Physics at the Autonomous University of Madrid (UAM) (2001). My PhD focused on the study of friction at the nanoscale in self-assembled monolayers as model lubricant by atomic force microscopy (AFM). One of the most relevant results was the correlation of energy losses to molecular events occurring at specific threshold loads [Phys. Rev. Lett. 82, 2880 (1999)]. In 2001 I acquired a postdoctoral position at the Max-Planck-Institute for Metal Research in Stuttgart (department of Prof. H. Dosch) to extend my experimental skills with synchrotron x-ray diffraction techniques applied to the structural research of organic semiconductor films. In 2002, I became the group leader of the organic group in the same department. The group aimed at advancing the understanding of growth and self-assembly mechanisms of organic semiconducting molecules by employing real-time x-ray diffraction experiments during the growth (from the vapor phase). The final goal was to control the morphology and structure of the organic materials to achieve enhanced the performance in devices. We could generally demonstrate the specific different molecular packing of the organic semiconductors at the dielectric interface and thickness-dependence structural transitions (JACS, 128, 15053 (2006), PRL 103, 136101 (2009)), results of relevance for organic field effect transistors. The research was extended to the investigation of polymers solar cells, in which the active layer is formed by a nanoscale mixture of electron donor and acceptor materials commonly deposited in solution. For that purpose we designed a drying channel that permitted to perform simultaneously x-ray diffraction and optical interferometry. We pioneered the in-situ study of film formation during solvent evaporation to understand the development phase separation and ordering of the donor and acceptor materials to identify the drying parameters that foster the formation of a more optimized nanomorphology for enhanced photovoltaic performance (Chapter “In situ Studies of Morphology Formation in Solution-Processed Polymer–Fullerene Blends” in book Elementary Processes in Organic Photovoltaics, Advances in Polymer Science, Springer).
At the end of 2009, I moved to the Institute of Materials Science of Barcelona (ICMAB-CSIC) as CSIC tenured scientist to open a new research line in the study of functional properties of organic semiconductors at nano- and molecular-scale with Prof. C. Ocal. We have stetted an ultra-high vacuum system of combined scanning tunneling and frequency modulation atomic force microscope (STM/FM-AFM) especially suitable for atomic-scale characterization of the interplay between electronic and geometric structure of organic semiconductors (Group of Physical Chemistry of Surfaces and Interfaces).
Short stays on other research centers:
08/2005-10/2005 as Research Fellow (two months) at International Center for Young Scientist (ICYS), at the National Institute for Materials Science (NIMS), Tsukuba, Japón.
2002-200 at the Max-Planck-Institut für Metallforschung (MF-MPI) /Universität Stuttgart 10/1997-
04/1998 at the Lawrence Berkeley National Laboratory, Berkeley, USA, in the group of M. Salmeron at the Center of Advanced Materials.
Divulgation of science:
Divulgation in schools (primary and secondary)Participation in “pint of science”, in 2015 and 2017Participation in the Theatralized reading “Madame du Châtelet i les seves seguidores a Instagram” to raise awareness about the role of women in science (for primary and secondary schools)
My research addresses fundamental interface properties at molecular-scale as well as nanoscale characterization of organic films in devices, such organic-field transistors and photovoltaics. Strong interest on organic doping and organic heterointerfaces. Expertise in grazing x-ray diffraction, organic growth, self-assembly, nanotribology, and scanning probe microscopies (STM, KPFM, C-AFM…).
Physics (Licenciatura) from the (Spanish: Universidad Autónoma de ; UAM), Spain
Doctorin Physics from the (Spanish: Universidad Autónoma de ; UAM), Spain. Work performed at the Institute of Materials Science of Madrid (ICMM-CSIC).
- Nanoscale characterization of organic films in devices (OFETs, OPV)
- Organic heterointerfaces
- Molecular self-assembly
- Structural characterization of organic layers by grazing incidence x-ray diffraction
- Advanced Scanning probe microscopies (STM, KPFM, C-AFM…)
E. Barrena, S. Kopta, D.F. Ogletree, D.H. Charych, M. Salmeron, “Relationship between Friction and Molecular Structure: Alkylsilane Lubricant Films under Pressure”, Phys. Rev. Lett. 82, 2880 (1999).
E. Barrena, C. Ocal, M. Salmeron, “Molecular packing changes of alkanethiols monolayers on Au(111) under applied pressure”, J. Chem. Phys. 113, 2413 (2000).
Molecular surface science:
E. Barrena, D.G. de Oteyza, H. Dosch, Y. Wakayama,“2D Supramolecular Self-Assembly of Binary Organic Monolayers”, ChemPhysChem 8, 1915 (2007).S. Matencio, R. Palacios-Rivera, J.I. Martínez, C. Ocal and E. Barrena, "Chiral organization and Charge Redistribution in Chloroaluminum Phtalocyanine on Au(111) Beyond the Monolayer" J. Phys. Chem, C (2018)
Organic growth and structural properties:
D.G. de Oteyza, E. Barrena, J.O. Ossó, S. Sellner, H. Dosch, “Thickness-dependent structural transitions in fluorinated copper-phthalocyanine (F16CuPc) films”, Journal of the American Chemical Society, 128, 15052 (2006).
B.N. Mbenkum, E.Barrena, X. Zhang, M. Kelsch, H. Dosch, “Selective Growth of Organic 1-D structures on Au Nanoparticles Arrays”, Nanoletters 6, 2852 (2006).
X. Zhang, E. Barrena, D. Goswami, D. G. de Oteyza, C. Weis, and H. Dosch “Evidence for layer-dependent Ehrlich-Schwöbel barrier in organic thin film growth” Physical Review Letters 103, 136101 (2009
Real-time film formation in polymer solar cells:
M. Sanyal, B. Schmidt-Hansberg, M. F.G. Klein, A. Colsmann, C. Munuera, A. Vorobiev, U. Lemmer, W. Schabel, H. Dosch, E. Barrena “In–situ x–ray study of drying temperature influence on the structural evolution of bulk heterojunction polymer–fullerene solar cells processed by doctor–blading” Advanced Energy Materials, 1, 362 ( 2011)
B. Schmidt-Hansberg, M. Sanyal, M. F. G. Klein, M. Pfaff, N.Schnabel, S. Jaiser, A. Vorobiev, E. Müller, A. Colsmann, P. Scharfer, D.Gerthsen, U. Lemmer, E. Barrena, W.Schabel “Moving through the Phase Diagram: Morphology Formation in Solution Cast Polymer_Fullerene Blend Films for Organic Solar Cells”, ACS Nano, 5, 8579 ( 2011)
Nanoscale characterization of OFETs:
M. Aghamohammadi, R.Rödel, U.Zschieschang, C. Ocal, H. Boschker, R. T. Weitz, E. Barrena, H. Klauk “Threshold-Voltage Shifts in Organic Transistors Due to Self-Assembled Monolayers at the Dielectric: Evidence for Electronic Coupling and Dipolar Effects”, Acs Applied Materials & Interfaces 7 22775 (2015)
Ana Pérez-Rodríguez, Inés Tremiño, Carmen Ocal, Marta Mas-Torrent, Esther Barrena, "Decoding the vertical phase separation and its impact on C8-BTBT:PS transistor properties", ACS Appl. Mater. Interfaces 10, (2018).