Dr. Gerardo Hernández-Sosa


Dr. Gerardo Hernández-Sosa
Light Technology Institute

Karlsruhe Institute of Technology
c/o InnovationLab
Speyerer Str. 4
69115 Heidelberg

contact via email
Phone: +49 (0) 6221 54 19 134 (iL)

Curriculum Vitae

Research Interest

Sustainable Technology, Printed Flexible Electronics, Biocompatible and Biodegradable Electronics.


  • 05/2009 Doktor der Technischen Wissenschaften, Institute for Semiconductors and Solid State Physics, Johannes Kepler University Linz, Austria.
    “Growth and Characterization of Para-sexiphenyl Nanostructures on Organic and Inorganic Substrates” Advisor: Prof. Dr. Helmut Sitter.

  • 06/2005 Masters in Applied Science (Semiconductors), Optical Communication Research Institute, Universidad Autónoma de San Luis Potosí, Mexico.
    “Growth and characterization of a-SixGe1-x:H(Er) alloys”
    Advisors: Dr. Angel G. Rodríguez-Vázquez and Dr. Miguel A. Vidal-Borbolla.

  • 09/2003 Bachelor in Physics Engineering, Universidad Autónoma de San Luis Potosí, Mexico. Bachelor in Physics Engineering, Universidad Autónoma de San Luis Potosí, Mexico.
    Final Grade Average: 9.2 (out of 10).

Professional Experience

  • 11/2014 Junior Research Group Leader, Karlsruhe Institute for Technology. Workplace at InnovationLab, Heidelberg, Germany.
    -Printed Biodegradable Optoelectronic Devices

  • 10/2011-10/2014 Postdoctoral Researcher, Karlsruhe Institute for Technology. Workplace at InnovationLab, Heidelberg, Germany.
    -Printed Optoelectronic Devices

  • 02/2010-06/2011 Postdoctoral Researcher, Center for Polymers and Organic Solids, University of California, Santa Barbara, USA.
    -Optical and electronic characterization of solution processed organic thin films for photovoltaic and light detection applications.

  • 06/2009-01/2010 Postdoctoral Researcher, Institute for Semiconductors and Solid State Physics, JKU Linz, Austria.
    -Growth and characterization of organic thin films and nanostructures on organic templates and modified surfaces by Hot Wall Epitaxy.

Invited Talks and Seminars

  • 08/2016 SPIE Optics + Photonics 2016 meeting, San Diego, USA

  • 09/2015 EuroMat Conference, Warsaw, Poland

  • 02/2015 Max Planck Institute for Polymer Research Mainz, Germany Group of Prof. Kurt Kremer

  • 03/2014 Linz Institute for Organic Solar Cells, Johannes Kepler University Linz, Austria. Group of Prof. Serdar Sariciftci

  • 03/2013 Center for Polymers and Organic Solids , University of California Santa Barbara USA Group of Prof. Alan Heeger

  • 09/2011 CIACYT, Universidad Autonoma de San Luis Potosi, Mexico Group of Prof. Hugo Navarro-Contreras

Awards and Grants

  • 11/2014-10/2018 Junior Research Group Grant -- BMBF NanoMatFutur Nachwuchswettbewerb.

  • 10/2005-01/2009 PhD Scholarship from the National Council of Science and Technology (CONACYT), Mexico.

Contribution to Scientific Organizations

  • Member of the Young Investigator Network of KIT.
  • Co-chair of the International Conference “Engineering and Life” sponsored by the Volskwagen foundation in Hanover, Germany, October 19th to 21st 2016

Reviewer Activities for Scientific Journals

  • Advanced Materials
  • Small
  • Organic Electronics
  • Advanced Electronic Materials
  • Optics Express
  • Synthetic Metals
  • Energy Technology


Author and co-author of 43 scientific publications in peer-reviewed journals, 8 peer-reviewed proceedings in international conferences, contribution in one book chapter and one patent application.

List of Publications

Peer-Reviewed Journals

  1. ACS Sustainable Chem. Eng. DOI: 10.1021/acssuschemeng.7b00675, April 2017
    Solution-Processed Bio-OLEDs with a Vitamin-Derived Riboflavin Tetrabutyrate Emission Layer
    Nils Jürgensen, Maximilian Ackermann, Tomasz Marszalek, Johannes Zimmermann, Anthony J. Morfa, Wojciech Pisula, Uwe H. F. Bunz, Felix Hinkel, and Gerardo Hernandez-Sosa
  2. Advanced Materials Technologies, vol. 2, no. 2, Feb. 2017.
    Slot Die Coated and Flexo Printed Highly Efficient SMOLEDs
    Sebastian M. Raupp, Dominik Daume, Serpil Tekoglu, Lisa Merklein, Uli Lemmer, Gerardo Hernandez-Sosa, Hans Martin Sauer, Edgar Dörsam, Philip Scharfer, and Wilhelm Schabel

  3. ACS Applied Materials & Interfaces, vol. 9, no. 3, pp. 2776-2785, Jan. 2017.
    Degradation Mechanisms in Organic Light-Emitting Diodes with Polyethylenimine as a Solution-Processed Electron Injection Layer
    Sebastian Stolz, Yingjie Zhang, Uli Lemmer, Gerardo Hernandez-Sosa, and Hany Aziz

  4. Sebastian Stolz, Martin Petzoldt, Naresh Notadiya, Tobias Rödlmeier, Ralph Eckstein, Jan Freudenberg, Uwe H. F. Bunz, Uli Lemmer, Eric Mankel, Manuel Hamburger, and Gerardo Hernández-Sosa.
    One-step additive crosslinking of conjugated polyelectrolyte interlayers: Improved lifetime and performance of solution-processed OLEDs.
    Journal of Materials Chemistry C, vol. 4, no. 47 pp. 11150-11156, Nov. 2016.

  5. Nils Jürgensen, Johannes Zimmermann, Anthony John Morfa, and Gerardo Hernández-Sosa.
    Biodegradable Polycaprolactone as Ion Solvating Polymer for Solution-Processed Light-Emitting Electrochemical Cells.
    Scientific Reports 6, Article number: 36643, Nov. 2016.

  6. Johannes Zimmermann, Nils Jürgensen, Anthony J. Morfa, Bohui Wang, Serpil Tekoglu, and Gerardo Hernández-Sosa.
    Poly(lactic-co-glycolic acid) (PLGA) as Ion-Conducting Polymer for Biodegradable Light-Emitting Electrochemical Cells.
    ACS Sustainable Chemistry & Engineering, Article ASAP.

  7. Anthony J. Morfa, Tobias Roedlmeier, Nils Juergensen, Sebastian Stolz, and Gerardo Hernández-Sosa.
    Comparison of biodegradable substrates for printed organic electronic devices.
    Cellulose, DOI: 10.1007/s10570-016-1049-0 (2016).

  8. Ralph Eckstein, Milan Alt, Tobias Rödlmeier, Philip Scharfer, Uli Lemmer,
    and Gerardo Hernández-Sosa.
    Digitally Printed Dewetting Patterns for Self-Organized Microelectronics.
    Advanced Materials, vol. 28, no. 35, pp. 7708-7715, Sep. 2016.

  9. Sebastian Stolz, Martin Petzoldt, Sebastian Dück, Michael Sendner, Uwe H. F. Bunz, Uli Lemmer, Manuel Hamburger, and Gerardo Hernández-Sosa.
    High-Performance Electron Injection Layers with a Wide Processing Window from an Amidoamine-Functionalized Polyfluorene.
    ACS Applied Materials & Interfaces, vol. 8, no. 20, pp. 12959–12967, May 2016.

  10. Markus Bender, Korwin M. Schelkle, Nils Jürgensen, Stefanie Schmid, Gerardo Hernández-Sosa, and Uwe H. F. Bunz.
    Photo-Cross-Linkable Polyfluorene–Triarylamine (PF–PTAA) Copolymer Based on the [2 + 2] Cycloaddition Reaction and Its Use as Hole-Transport Layer in OLEDs.
    Macromolecules, vol. 49, no. 8, pp. 2957–2961, Apr. 2016.

  11. Serpil Tekoglu, Martin Petzoldt, Sebastian Stolz, Uwe H.F. Bunz, Uli Lemmer, Manuel Hamburger, and Gerardo Hernández-Sosa.
    Emissive Polyelectrolytes as Interlayer for Color-tuning and Electron Injection in Solution-processed Light-emitting Devices.
    ACS Applied Materials & Interfaces, vol. 8, no. 11, pp. 7320–7325, Feb. 2016.

  12. Milan Alt, Christian Melzer, Florian Mathies, Kaja Deing, Gerardo Hernández-Sosa, and Uli Lemmer.
    Adjustable passivation of SiO2 trap states in OFETs by an ultrathin CVD deposited polymer coating.
    Applied Physics A, vol. 122, no. 204, Mar. 2016.

  13. Sabina Hillebrandt, Torben Adermann, Milan Alt, Janusz Schinke, Tobias Glaser, Eric Mankel, Gerardo Hernández-Sosa, Wolfram Jaegermann, Uli Lemmer, Annemarie Pucci, Wolfgang Kowalsky, Klaus Müllen, Robert Lovrinčić, and Manuel Hamburger.
    Naphthalene tetracarboxy-diimide based n-type polymers with removable solubility via thermally cleavable side chains.
    ACS Applied Materials & Interfaces, vol. 8, no. 7, pp. 4940-4945, Feb 2016.

  14. Milan Alt, Malte Jesper, Janusz Schinke, Sabina Hillebrandt, Patrick Reiser, Tobias Rödlmeier, Iva Angelova, Kaja Deing, Tobias Glaser, Eric Mankel, Wolfram Jaegermann, Annemarie Pucci, Uli Lemmer, Uwe H. F. Bunz, Wolfgang Kowalsky, Gerardo Hernández-Sosa, Robert Lovrinčić, and Manuel Hamburger.
    The Swiss-Army-Knife Self-Assembled Monolayer: Improving Electron Injection, Stability, and Wettability of Metal Electrodes with a One-Minute Process.
    Advanced Functional Materials, vol. 26, no. 18, pp. 3172-3178, May 2016.

  15. Sivaramakrishnan Sankaran, Konstantin Glaser, Stefan Gärtner, Tobias Rödlmeier, Kai Sudau, Gerardo Hernández-Sosa, and Alexander Colsmann.
    Fabrication of polymer solar cells from organic nanoparticle dispersions by doctor blading or ink-jet printing.
    Organic Electronics, vol. 28, pp. 118-122, Jan. 2016.

  16. Ralph Eckstein, Tobias Roedlmeier, Tobias Glaser, Sebastian Valouch, Ralf Mauer, Uli Lemmer, and Gerardo Hernández-Sosa.
    Aerosol-Jet Printed Flexible Organic Photodiodes: Semi-Transparent, Color Neutral, and Highly Efficient.
    Advanced Electronic Materials, vol. 1, no. 8, p 1500101, Aug. 2015.

  17. Milan Alt, Janusz Schinke, Sabina Hillebrandt, Marc Hänsel, Gerardo Hernández-Sosa, Norman Mechau, Tobias Glaser, Eric Mankel, Manuel Hamburger, Kaja Deing, Wolfram Jaegermann, Annemarie Pucci, Wolfgang Kowalsky, Uli Lemmer, and Robert Lovrinčić.
    Processing Follows Function: Pushing the Formation of Self-Assembled Monolayers to High-Throughput Compatible Time Scales.
    ACS Applied Materials & Interfaces, vol. 6, no. 22, pp. 20234-20241, Nov. 2014.

  18. Michal Radziwon, Gerardo Hernández-Sosa, Christoph Lackner, Helmut Sitter, Clemens Simbrunner.
    Motionless system to measure relative angular emission intensity of decaying or modulated light emitting diodes.
    Review of Scientific Instruments, vol. 85, no. 10, p. 103103, Oct. 2014.

  19. Fabian Markl, Ingo Braun, Emanuel Smarsly, Uli Lemmer, Norman Mechau, Gerardo Hernández-Sosa, and Uwe H. F. Bunz.
    Printing PPEs: Fundamental Structure–Property Relationships.
    ACS Macro Letters, vol. 3, no. 8, pp. 788-790, Aug. 2014.

  20. Ralph Eckstein, Gerardo Hernández-Sosa, Uli Lemmer, and Norman Mechau.
    Aerosol jet printed top grids for organic optoelectronic devices.
    Organic Electronics, vol. 15, no. 9, pp. 2135-2140, Sep. 2014.

  21. Sebastian Stolz, Michael Scherer, Eric Mankel, Robert Lovrinčić, Janusz Schinke, Wolfgang Kowalsky, Wolfram Jaegermann, Uli Lemmer, Norman Mechau, and Gerardo Hernández-Sosa.
    Investigation of Solution-Processed Ultrathin Electron Injection Layers for Organic Light-Emitting Diodes.
    ACS Applied Materials & Interfaces, vol. 6, no. 9, pp. 6616–22, May 2014.

  22. Stefan Hengen, Milan Alt, Gerardo Hernández-Sosa, Jürgen Giehl, Uli Lemmer, and Norman Mechau.
    Modelling and simulation of gate leakage currents of solution-processed OTFT.
    Organic Electronics, vol. 15, no. 3, pp. 829–834, Mar. 2014.

  23. Gerardo Hernández‐Sosa, Serpil Tekoglu, Sebastian Stolz, Ralph Eckstein, Claudia Teusch, Jannik Trapp, Uli Lemmer, Manuel Hamburger, and Norman Mechau.
    The Compromises of Printing Organic Electronics: A Case Study of Gravure-Printed Light-Emitting Electrochemical Cells.
    Advanced Materials, vol. 26, no. 20, pp. 3235-3240, May 2014.

  24. Serpil Tekoglu, Gerardo Hernández-Sosa, Edgar Kluge, Uli Lemmer, and Norman Mechau.
    Gravure printed flexible small-molecule organic light emitting diodes.
    Organic Electronics, vol. 14, no. 12, pp. 3493–3499, Dec. 2013.

  25. Gerardo Hernández-Sosa, Ralph Eckstein, Serpil Tekoglu, Tobias Becker, Florian Mathies, Uli Lemmer, and Norman Mechau.
    The role of the polymer solid electrolyte molecular weight in light-emitting electrochemical cells.
    Organic Electronics, vol. 14, no. 9, pp. 2223–2227, Sep. 2013.

  26. Gerardo Hernández-Sosa, Nils Bornemann, Ingo Ringle, Michaela Agari, Edgar Doersam, Norman Mechau, and Uli Lemmer.
    Rheological and drying considerations for uniformly gravure-printed layers: towards large-area flexible organic light-emitting diodes.
    Advanced Functional Materials, vol. 23, no. 25, pp. 3164–3171, Jul. 2013.

  27. Advanced Materials, vol. 25, no. 2, pp. 256-260, Jan. 2013.
    High Efficiency Panchromatic Hybrid Schottky Solar Cells.
    Joun Lee, Syed Mubeen, Gerardo Hernández -Sosa, Yanming Sun, Francesca M. Toma, Galen D. Stucky, and Martin Moskovits.

  28. Advanced Functional Materials, vol. 22, no. 15, pp. 3279-3283, Apr. 2012.
    New Configuration of Solid-State Neutron Detector Made Possible with Solution-Based Semiconductor Processing.
    Huiqiong Zhou, Nelson E. Coates, Gerardo Hernández -Sosa, and Daniel Moses.

  29. Journal of Materials Chemistry, vol. 22, pp. 15316-15325, 2012.
    Alternately deposited heterostructures of α-sexithiophene–para-hexaphenyl on muscovite mica(001) surfaces: crystallographic structure and morphology.
    Tatjana Djuric, Gerardo Hernández -Sosa, Günther Schwabegger, Markus Koini, Günter Hesser, Martin Arndt, Martin Brinkmann, Helmut Sitter, Clemens Simbrunner, and Roland Resel.

  30. ACS Nano, vol. 6, no. 6, pp. 4629-4638, Jun. 2012.
    Color Tuning of Nanofibers by Periodic Organic–Organic Hetero-Epitaxy.
    Clemens Simbrunner, Gerardo Hernández-Sosa, Francesco Quochi, Günther Schwabegger, Chiara Botta, Martin Oehzelt, Ingo Salzmann, Tatjana Djuric, Alfred Neuhold, Roland Resel, Michele Saba, Andrea Mura, Giovanni Bongiovanni, Antje Vollmer, Norbert Koch, and Helmut Sitter.

  31. Applied Physics A, vol. 107, no. 4, pp. 985-993, Jun. 2012.
    Photo-Fries-based photosensitive polymeric interlayers for patterned organic devices.
    Alberto Montaigne Ramil, Gerardo Hernández-Sosa, Thomas Griesser, Clemens Simbrunner, Thomas Höfler, Gregor Trimmel, Wolfgang Kern, Quan Shen, Christian Teichert, Günther Schwabegger, Helmut Sitter, and Niyazi Serdar Sariciftci.

  32. Advanced Materials, vol. 24, no. 17, pp. 2273-2277, May 2012.
    Manifestation of Carrier Relaxation Through the Manifold of Localized States in PCDTBT:PC60BM Bulk Heterojunction Material: The Role of PC84BM Traps on the Carrier Transport.
    Wei Lin Leong, Gerardo Hernández-Sosa, Sarah R. Cowan. Daniel Moses and Alan J. Heeger.

  33. Nano Letters, vol. 11, no. 12, pp. 5548-5552, 2011.
    Plasmonic Photosensitization of a Wide Band Gap Semiconductor: Converting Plasmons to Charge Carriers.
    Syed Mubeen, Gerardo Hernández-Sosa, Daniel Moses, Joun Lee, and Martin Moskovits.

  34. Applied Physics Letters, vol. 99, no. 16, 2011.
    Extension of the spectral responsivity of the photocurrent in solution-processed small molecule composite via a charge transfer excitation.
    Gerardo Hernández-Sosa, Minghong Tong, Nelson E. Coates, Sebastian Valouch, and Daniel Moses.

  35. Physical Review B, vol. 83, no. 11, Mar. 2011.
    Epitaxial Growth of Sexithiophene on Mica Surfaces.
    Clemens Simbrunner, Gerardo Hernández-Sosa, Martin Oehzelt, Tatjana Djuric, Ingo Salzmann, Martin Brinkmann, Günther Schwabegger, Irene Watzinger, Helmut Sitter, and Roland Resel.

  36. Advanced Functional Materials, vol. 21, no. 5, pp. 927-931, Mar. 2011.
    High photoconductive responsivity in solution-processed poly-crystalline organic composite films.
    Gerardo Hernández-Sosa, Nelson E. Coates, Sebastian Valouch, and Daniel Moses.

  37. Journal of the American Chemical Society, vol. 133, no. 9, pp. 3056-3062, 2011.
    Epitaxy of Rodlike Organic Molecules on Sheet Silicates—A Growth Model Based on Experiments and Simulations.
    Clemens Simbrunner, Dmitrii Nabok, Gerardo Hernández-Sosa, Martin Oehzelt, Tatjana Djuric, Roland Resel, Lorenz Romaner, Peter Puschnig, Claudia Ambrosch-Draxl, Ingo Salzmann, Günther Schwabegger, Irene Watzinger, and Helmut Sitter.

  38. ACS Nano, vol. 4, no. 10, pp. 6244-6250, Oct. 2010.
    Organic-Organic Heteroepitaxy of Red-,Green-, and Blue-Emitting Nanofibers.
    Clemens Simbrunner, Francesco Quochi, Gerardo Hernández-Sosa, Martin Oehzelt, Roland Resel, Günter Hesser, Martin Arndt, Michele Saba, Andrea Mura, Giovanni Bongiovanni, and Helmut Sitter.

  39. Applied Physics A, vol. 98, no. 337, 2010.
    Quantitative luminous efficiency determination for large-area light-emitting devices.
    Clemens Simbrunner, Gerardo Hernández-Sosa, and Helmut Sitter.

  40. Applied Physics Letters, vol. 95, no. 1, 013306, 2009.
    Growth and optical properties of alpha-Sexithiophene doped Para-sexiphenyl nanofibers.
    Gerardo Hernández-Sosa, Clemens Simbrunner, and Helmut Sitter.

  41. Organic Electronics, vol. 10, no. 3, pp. 408-415, May 2009.
    Small Molecule Vacuum Processed Melamine-C60, Organic Field Effect Transistor.
    Mihai Irimia-Vladu, Nenad Marjanovic, Marius Bodea, Gerardo Hernández-Sosa, Alberto Montaigne Ramil, Reinhard Schwödiauer, Siegfried Bauer, Niyazi Serdar Sariciftci, Frank Nüesch.

  42. Applied Physics Letters, vol. 94, no. 7, 073505, 2009.
    Para-Sexiphenyl-CdSe/ZnS Nanocrystal Hybrid Light Emitting Diodes.
    Clemens Simbrunner, Gerardo Hernández-Sosa, Eugen Baumgartner, Günter Hesser, Jürgen Roither, Wolfgang Heiss, and Helmut Sitter.

  43. The Journal of Chemical Physics, vol. 130, no. 8, 084901, 2009.
    Origin of the low-energy emission band in epitaxially grown para-sexiphenyl nanocrystallites.
    Andrey Kadashchuk, Yu. Skryshevski, Yu. Piryatinski, Igor Beynik, Christian Teichert, Gerardo Hernández-Sosa, Helmut Sitter, Andrei Andreev, Paul Frank, and Adolf Winkler.

  44. Organic Electronics, vol. 10, no. 2, pp. 326-332, Apr. 2009.
    Modification of Para-sexiphenyl layer growth by UV induced polarity changes of polymeric substrates.
    Gerardo Hernández-Sosa, Clemens Simbrunner, T. Höfler, A. Moser, O. Werzer, B. Kunert, G. Trimmel, W. Kern, R. Resel, and Helmut Sitter.

  45. Advanced Materials, vol. 20, no. 20, pp. 3887-3892, Oct. 2008.
    Vacuum processed polyaniline-C60 , organic field effect transistors.
    Mihai Irimia-Vladu, Nenad Marjanovic, Angela Vlad, Alberto Montaigne Ramil, Gerardo Hernández-Sosa, Reinhard Schwodiauer, Siegfried Bauer, and Niyazi Serdar Sariciftci.

  46. Journal of Crystal Growth, vol. 310, no. 7-9, pp. 1772-1776, Apr. 2008.
    Fe onto GaN(0001) grown in a full MOVPE process.
    Andrea Navarro-Quezada, Tian Li, Clemens Simbrunner, M Kiecana, Gerardo Hernández-Sosa, M. Quast, M. Wegscheider, M. Sawicki, T. Dietl, and A. Bonanni.

  47. Thin Solid Films, vol. 516, no. 10, pp. 2939-2942, Mar. 2008.
    Search for a wetting layer in thin film growth of para-hexaphenyl on KCl(001).
    Paul Frank, Gerardo Hernández-Sosa, Helmut Sitter, and Adolf Winkler.

  48. Chemical Physics Letters, vol. 446, no. 1-3, pp. 83-86, Sep. 2007.
    Two-photon absorption induced photoluminescence in para-sexiphenyl nanoneedles.
    Kang-Jun  Liu, Gerardo Hernández-Sosa, Helmut Sitter, Chun-Feng Zhang, Zhi-Wei Dong, Yong-Li Yan, and Shi-Xiong Qian.

  49. Physica Status Solidi B, vol. 243, no. 13, pp. 3329-3332, Nov. 2006.
    Electrical transport properties of hot wall epitaxially grown para-sexiphenyl nano-needles.
    Th. B. Singh, Gerardo Hernández-Sosa, H. Neugebauer, Andrei Andreev, Helmut Sitter, and Niyazi Serdar Sariciftci

Book Chapters

  1. Springer Series in Materials Science, vol. 173, pp. 49-78, 2013.
    Organic–Organic Heteroepitaxy—The Method of Choice to Tune Optical Emission of Organic Nano-fibers?
    Clemens Simbrunner , Gerardo Hernández-Sosa, Martin Oehzelt, Roland Resel, Francesco Quochi, Dimitrii Nabok, Tatjana Djuric, Lorenz Romaner, Peter Puschnig, Claudia Draxl, Ingo Salzmann, Günther Schwabegger, Irene Watzinger, Michele Saba, Andrea Mura, Giovanni Bongiovanni, and Helmut Sitter.


  1. U.S. patent Aplication: US2014/0079874 A1
    Method and device for printing functional layers for electronic components
    Michaela Agari, Gerardo Hernández-Sosa, Ingo Ringle, Norman Mechau, Andreas Rupprecht