Karlsruhe Institute of Technology (LTI)

The Device Physics Competence Center is led by the Printed Electronics research group of the Light Technology Institute (LTI) headed by Prof. Uli Lemmer and Dr. Gerardo Hernandez-Sosa from the Karlsruhe Institute of Technology (KIT).

The Printed Electronics group of LTI investigates materials and advanced device architectures for the fabrication of optoelectronic systems by industrially relevant techniques. A central part of the research activities is the development of ink formulations and printing processes to control the performance of printed devices. Moreover, we investigate the integration of printed organic electronic devices in complex systems. Hernandez-Sosa BMBF funded junior research group works on the use of biodegradable/biocompatible materials for the fabrication of optoelectronic devices. The rationale is the combination of state-of-the-art high-throughput printing techniques with the topic of more sustainable and “Greener” technologies. 

 Fully Digitally Printed Image Sensor Based on Organic Photodiodes
Ralph Eckstein, Noah Strobel, Tobias Rödlmeier, Konstantin Glaser, Uli Lemmer, Gerardo Hernandez‐Sosa
Advanced Optical Materials 1701108, (2018)

 Fully Printed Light‐Emitting Electrochemical Cells Utilizing Biocompatible Materials
Johannes Zimmermann, Luca Porcarelli, Tobias Rödlmeier, Ana Sanchez‐Sanchez, David Mecerreyes, Gerardo Hernandez‐Sosa
Advanced Functional Materials, 170595 (2017)

Sulfone-Based Deep Blue Thermally Activated Delayed Fluorescence Emitters: Solution-Processed Organic Light-Emitting Diodes with High Efficiency and Brightness
Nils Jürgensen, Andreas Kretzschmar, Stefan Höfle, Jan Freudenberg, Uwe HF Bunz, Gerardo Hernandez-Sosa
Chemistry of Materials, 29, 9154 (2017)

Semiconductor: Insulator Blends for Speed Enhancement in Organic Photodiodes
Noah Strobel, Ralph Eckstein, Jonathan Lehr, Uli Lemmer, Gerardo Hernandez‐Sosa
Advanced Electronic Materials, 1700345 (2017)

Controlled Molecular Orientation of Inkjet Printed Semiconducting Polymer Fibers by Crystallization Templating
Tobias Rödlmeier, Tomasz Marszalek, Martin Held, Sebastian Beck, Christian Müller, Ralph Eckstein, Anthony J Morfa, Robert Lovrincic, Annemarie Pucci, Uli Lemmer, Jana Zaumseil, Wojciech Pisula, Gerardo Hernandez-Sosa
Chemistry of Materials, 29, 10150 (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 HF Bunz, Felix Hinkel, Gerardo Hernandez-Sosa
ACS Sustainable Chem. Eng. 5, 5368 (2017)

Digitally Printed Dewetting Patterns for Self‐Organized Microelectronics
Ralph Eckstein, Milan Alt, Tobias Rödlmeier, Philip Scharfer, Uli Lemmer, Gerardo Hernandez‐Sosa
Advanced Materials, 28, 7708 (2016)

Group Leader

Dr. Gerardo Hernandez-Sosa

Head of the Printed Electronics Group and BMBF Junior Group BioLICHT (iL)
contact via email
Room: E 4.02

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

Postdoctoral Researchers

Martin Held, M. Sc.

Postdoctoral Researcher
contact via email
Room: F 4.13

Phone: +49 (0) 6221 54 19 140 (iL)

PhD Students

Nils Juergensen, M. Sc.

PhD student
contact via email

Phone: +49 (0) 6221 54 19 140 (iL)

Tobias Roedlmeier, M. Sc.

PhD student
contact via email
Room: E 4.02

Phone: +49 (0) 6221 54 19 122 (iL)

Stefan Schlisske, M. Sc.

PhD student
contact via email
Room: E 4.02

Phone: +49 (0) 6221 54 19 122 (iL)

Noah Strobel, M. Sc.

PhD student
contact via email
Room: E 4.02

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

Johannes Zimmermann, M. Sc.

PhD student
contact via email

Phone: +49 (0) 6221 54 19 140 (iL)

Mervin Seiberlich, M. Sc.

PhD Student

contact via email

Room: E 4.13

Phone: +49 (0) 6221 54 19 122 (iL)

Manuel Pietsch, M. Sc.

Master student, Heidelberg University
contact via email
Room: E 4.13

Phone: +49 (0) 6221 54 19 140 (iL)

Master & Bachelor

Former Members

Doctoral Researchers:

  • Sebastian Stolz, Dr. -Ing. [Merk KGaA]
  • Ralph Eckstein, Dr.-Ing.    [Dentsply Sirona]
  • Florian Mathies, Dr.-Ing.   [Helmholtz-Zentrum Berlin]

Posdoctoral Researchers:

  • Anthony Morfa, Dr.          [The University of Sydney]
  1. Adv. Optical. Mater. doi: adom20.1701108 (2018)
    “Fully Digitally Printed Image Sensor Based on Organic Photodiodes”
    R. Eckstein, N. Strobel, U. Lemmer, G. Hernandez-Sosa
  2. IEEE Sensors Journal 18, 494 (2018)
    “SnO2 Nanowire-Based Aerosol Jet Printed Electronic Nose as Fire Detector”

    M. Adib, R. Eckstein, G. Hernandez-Sosa, M. Sommer, U. Lemmer
  3. Adv. Funct. Mater., 1705795 (2018)
    “Fully Printed Light-emitting Electrochemical Cells Utilizing Biocompatible Materials

    J. Zimmermann, L. Porcarelli, T. Rödlmeier, A. Sanchez-Sanchez, D. Mecerreyes, G. Hernandez-Sosa
  4. Opt. Express 26, A144-A152 (2018)
    “Inkjet Printed Perovskite Distributed Feedback Lasers”

    F. Mathies, P. Brenner, G. Hernandez-Sosa, I. Howard, U. W. Paetzold and U. Lemmer
  5. Adv. Electron. Mater., 1700345 (2017)
    “Semiconductor : Insulator Blends for Speed Enhancement in Organic Photodiodes”
    N. Strobel, R. Eckstein, J. Lehr, U. Lemmer, G. Hernandez-Sosa
  6. Chem. Mater., 29, 10150 (2017)
    “Controlled Molecular Orientation of Inkjet Printed Semiconducting Polymer Fibers by Crystallization Templating”

    T. Rödlmeier, S. Beck, M. Held, T. Marzsalek, C. Müller, R. Eckstein, A. J. Morfa, W. Pisula, R. Lovrincic, J. Zaumseil, A. Pucci, U. Lemmer, G. Hernandez-Sosa
  7. Adv. Mater. Technol., 1700236 (2017)
    “Digital Aerosol Jet Printing for the Fabrication of Terahertz Metamaterials”

    D. Jahn, R. Eckstein, L. M. Schneider, N. Born, G. Hernandez-Sosa, J. C. Balzer, I. Al-Naib, U. Lemmer, and M. Koch
  8. Chem. Mater., 29, 9154 (2017)
    “Sulfone-Based Deep Blue TADF Emitters: Solution-Processed OLEDs with High Efficiency and Brightness”

    N. Jürgensen, A. Kretzschmar, S. Höfle, J. Freudenberg, U. H. F. Bunz, G. Hernandez-Sosa
  9. Sensors, 17, 2401 (2017)
    “Lab-on-chip surface-enhanced Raman analysis by aerosol jet printing and roll-to-roll hot embossing”  A. Habermehl, N. Strobel, R. Eckstein, N. Bolse, A. Mertens, G. Hernandez-Sosa, C. Eschenbaum, U. Lemmer
  10. ACS Omega, 2, 6500 (2017)
    "Reliability of Aerosol Jet Printed Fluorescence Quenching Sensor Arrays for the Identification and Quantification of Explosive Vapors"

    N. Bolse, R. Eckstein, A. Habermehl, G. Hernandez-Sosa, C. Eschenbaum, U. Lemmer
  1. Applied Optics, 56, 7774 (2017)
    Electrical and optical properties of reduced graphene oxide thin film deposited onto polyethylene terephthalate by spin coating technique

    H. A. Rivera Tito, A. Habermehl, C. Müller, S. Beck, C. Romero Nieto, G. Hernandez-Sosa, M. E. Quintana Caceda
  2. Light-Emitting Electrochemical Cells: Concepts, Advances, and Challenges (Ed. R. Costa) Springer (2017)
    Morphology Engineering and Industrial Relevant Device Processing of Light-Emitting Electrochemical Cells
    G. Hernandez-Sosa, A. J. Morfa, N. Jürgensen, S. Tekoglu, J. Zimmermann
  3. Applied Optics, 56,  6476 (2017)
    Simple light-emitting electrochemical cell using reduced graphene oxide and a ruthenium (II) complex

    H. A. Rivera Tito, J. Zimmermann, N. Jürgensen, G. Hernandez-Sosa, and M. E. Quintana Caceda  
  4. ACS Omega Accepted (2017)
    Reliability of Aerosol Jet Printed Fluorescence Quenching Sensor Arrays for the Identification and Quantification of Explosive Vapors
    N. Bolse, R. Eckstein, A. Habermehl, G. Hernandez-Sosa, C. Eschenbaum, U. Lemmer
  5. Organic Electronics 50, 384 (2017)
    Electron Injection and Interfacial Trap Passivation in Solution-Processed Organic Light-Emitting Diodes by a Poly(Sulfobetaine Methacrylate) Interlayer
    M. Ruscello, S. Stolz, D. L. Gonzalez Arellano, F. Ullrich, S. Hillebrandt, E. Mankel, T. Emrick, A. Pucci, W. Kowalsky, A. L. Briseno, G. Hernandez-Sosa
  6. Optics Express 25 (15), 18092 (2017)
    Multispectral Electroluminescence Enhancement of (6,5) Single-Walled Carbon Nanotubes Coupled to Periodic Nanodisk Arrays
    Y. Zakharko, M. Held, A. Graf, T. Rödlmeier, R. Eckstein, G. Hernandez-Sosa, B. Hähnlein, J. Pezoldt, J. Zaumseil
  7. ACS Sustainable Chem. Eng. 5, 5368 (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
  8. 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 
  9. 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
  10.  Journal of Materials Chemistry C, vol. 4, no. 47 pp. 11150-11156, Nov. 2016.
    One-step additive crosslinking of conjugated polyelectrolyte interlayers: Improved lifetime and performance of solution-processed OLEDs
    Sebastian Stolz, Martin Petzoldt, Naresh Notadiya, Tobias Rödlmeier, Ralph Eckstein, Jan Freudenberg, Uwe H. F. Bunz, Uli Lemmer, Eric Mankel, Manuel Hamburger, and Gerardo Hernandez-Sosa 
  11. Scientific Reports 6, Article number: 36643, Nov. 2016.
    Biodegradable Polycaprolactone as Ion Solvating Polymer for Solution-Processed Light-Emitting Electrochemical Cells

    Nils Jürgensen, Johannes Zimmermann, Anthony John Morfa, and Gerardo Hernandez-Sosa 
  12. ACS Sustainable Chemistry & Engineering, 4 (12), pp 7050–7055 Sep. 2016.
    Poly(lactic-co
    -glycolic acid) (PLGA) as Ion-Conducting Polymer for Biodegradable Light-Emitting Electrochemical Cells
    Johannes Zimmermann, Nils Jürgensen, Anthony J. Morfa, Bohui Wang, Serpil Tekoglu, and Gerardo Hernandez-Sosa
  13. Cellulose, vol. 23, no. 110, pp. 1-9, 2016.
    Comparison of biodegradable substrates for printed organic electronic devices

    Anthony J. Morfa, Tobias Rödlmeier, Nils Jürgensen, Sebastian Stolz, and Gerardo Hernandez-Sosa 
  14. Advanced Materials, vol. 28, no. 35, pp. 7708-7715, Sep. 2016.
    Digitally Printed Dewetting Patterns for Self-Organized Microelectronics

    Ralph Eckstein, Milan Alt, Tobias Rödlmeier, Philip Scharfer, Uli Lemmer, and Gerardo Hernandez-Sosa 
  15. ACS Applied Materials & Interfaces, vol. 8, no. 20, pp. 12959–12967, May 2016.
    High-Performance Electron Injection Layers with a Wide Processing Window from an Amidoamine-Functionalized Polyfluorene

    Sebastian Stolz, Martin Petzoldt, Sebastian Dück, Michael Sendner, Uwe H. F. Bunz, Uli Lemmer, Manuel Hamburger, and Gerardo Hernandez-Sosa
  16. Advanced Functional Materials, vol. 26, no. 18, pp. 3172-3178, May 2016.
    The Swiss-Army-Knife Self-Assembled Monolayer: Improving Electron Injection, Stability, and Wettability of Metal Electrodes with a One-Minute Process

    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 Lemmer1, U. H. F. Bunz, W. Kowalsky, G. Hernandez-Sosa, R. Lovrinčić, and M. Hamburger
  17. Macromolecules, vol. 49, no. 8, pp. 2957–2961, Apr. 2016.
    Photo-Cross-Linkable Polyfluorene–Triarylamine (PF–PTAA) Copolymer Based on the [2 + 2] Cycloaddition Reaction and Its Use as Hole-Transport Layer in OLEDs

    Markus Bender, Korwin M. Schelkle, Nils Jürgensen, Stefanie Schmid, Gerardo Hernandez-Sosa, and Uwe H. F. Bunz 
  18. Applied Physics A, vol. 122, no. 3, pp. 1-7, Mar. 2016.
    Adjustable passivation of SiO2 trap states in OFETs by an ultrathin CVD deposited polymer coating

    Milan Alt, Christian Melzer, Florian Mathies, Kaja Deing, Gerardo Hernandez-Sosa, and Uli Lemmer 
  19. ACS Applied Materials & Interfaces, vol. 8, no. 11, pp. 7320–7325, Feb. 2016.
    Emissive Polyelectrolytes as Interlayer for Color-tuning and Electron Injection in Solution-processed Light-emitting Devices

    Serpil Tekoglu, Martin Petzoldt, Sebastian Stolz, Uwe H.F. Bunz, Uli Lemmer, Manuel Hamburger, and Gerardo Hernandez-Sosa 
  20. ACS Applied Materials & Interfaces, vol. 8, no. 7, pp. 4940-4945, Feb 2016.
    Naphthalene tetracarboxy-diimide based n-type polymers with removable solubility via thermally cleavable side chains

    Sabina Hillebrandt, Torben Adermann, Milan Alt, Janusz Schinke, Tobias Glaser, Eric Mankel, Gerardo Hernandez-Sosa, Wolfram Jaegermann, Uli Lemmer, Annemarie Pucci, Wolfgang Kowalsky, Klaus Müllen, Robert Lovrinčić, and Manuel Hamburger 
  21. Organic Electronics, vol. 28, pp. 118-122, Jan. 2016.
    Fabrication of polymer solar cells from organic nanoparticle dispersions by doctor blading or ink-jet printing

    Sivaramakrishnan Sankaran, Konstantin Glaser, Stefan Gärtner, Tobias Rödlmeier, Kai Sudau, Gerardo Hernandez-Sosa, and Alexander Colsmann 
  22. Langmuir, vol. 31, no. 37, pp. 10303-10309, Sep. 2015.
    Dipolar SAMs Reduce Charge Carrier Injection Barriers in n-Channel Organic Field Effect Transistor

    Malte Jesper, Milan Alt, Janusz Schinke, Sabina Hillebrandt, Iva Angelova, Valentina Rohnacher, Annemarie Pucci, Uli Lemmer, Wolfram Jaegermann, Wolfgang Kowalsky, Tobias Glaser, Eric Mankel, Robert Lovrinčić, Florian Golling, Manuel Hamburger, and Uwe H. F. Bunz 
  23. Advanced Electronic Materials, vol. 1, no. 8, p 1500101, Aug. 2015.
    Aerosol-Jet Printed Flexible Organic Photodiodes: Semi-Transparent, Color Neutral, and Highly Efficient

    Ralph Eckstein, Tobias Roedlmeier, Tobias Glaser, Sebastian Valouch, Ralf Mauer, Uli Lemmer, and Gerardo Hernandez-Sosa 
  24. Physica Status Solidi B, vol. 252, no. 6, pp. 1272-1279, Jun. 2015.
    Impedance spectroscopy: A method for determining the degree of intermixing in stacks of organic semiconductors

    Robert Tone, Nils Bornemann, Norman Mechau, and Edgar Dörsam 

  1. The Journal of Organic Chemistry, vol. 80, no. 1, pp. 582-589, Jan. 2015.
    Soluble Diazaiptycenes: Materials for Solution-Processed Organic Electronics

    Philipp Biegger, Sebastian Stolz, Sebastian N. Intorp, Yexiang Zhang, Jens U. Engelhart, Frank Rominger, Kenneth I. Hardcastle, Uli Lemmer, Xuhong Qian, Manuel Hamburger, and Uwe H. F. Bunz 
  2. ACS Applied Materials & Interfaces, vol. 6, no. 22, pp. 20234-20241, Nov. 2014.
    Processing Follows Function: Pushing the Formation of Self-Assembled Monolayers to High-Throughput Compatible Time Scales

    Milan Alt, Janusz Schinke, Sabina Hillebrandt, Marc Hänsel, Gerardo Hernandez-Sosa, Norman Mechau, Tobias Glaser, Eric Mankel, Manuel Hamburger, Kaja Deing, Wolfram Jaegermann, Annemarie Pucci, Wolfgang Kowalsky, Uli Lemmer, and Robert Lovrincic 
  3. Review of Scientific Instruments, vol. 85, no. 10, p. 103103, Oct. 2014.
    Motionless system to measure relative angular emission intensity of decaying or modulated light emitting diodes

    Michal Radziwon, Gerardo Hernandez-Sosa, Christoph Lackner, Helmut Sitter, Clemens Simbrunner 
  4. Organic Electronics, vol. 15, no. 9, pp. 2135-2140, Sep. 2014.
    Aerosol jet printed top grids for organic optoelectronic devices

    Ralph Eckstein, Gerardo Hernandez-Sosa, Uli Lemmer, and Norman Mechau 
  5. Langmuir, vol. 31, no. 37, pp. 10303–10309, Sep. 2015.
    Dipolar SAMs Reduce Charge Carrier Injection Barriers in n-Channel Organic Field Effect Transistors

    Malte Jesper, Milan Alt, Janusz Schinke, Sabina Hillebrandt, Iva Angelova,  Valentina Rohnacher, Annemarie Pucci, Uli Lemmer, Wolfram Jaegermann, Wolfgang Kowalsky, Tobias Glaser, Eric Mankel, Robert Lovrincic, Florian Golling, Manuel Hamburger, Uwe H. F. Bunz 
  6. Organic Electronics, vol. 15, no. 9, pp. 2135-2140, Sep. 2014.
    Aerosol jet printed top grids for organic optoelectronic devices
    Ralph Eckstein, Gerardo Hernandez-Sosa, Uli Lemmer, and Norman Mechau 
  7. Journal of Materials Chemistry C 2, pp. 7934-7942, Aug. 2014.
    Impact of processing on the chemical and electronic properties of phenyl-C-61-butyric acid methyl ester

    J. Maibach, T. Adermann, T. Glaser, Ralph Eckstein, Eric Mankel, Annemarie Pucci, Klaus Müllen, Uli Lemmer, Manuel Hamburger, T. Mayer, and Wolfram Jaegermann

  1. ACS Macro Letters, vol. 3, no. 8, pp. 788-790, Aug. 2014.
    Printing PPEs: Fundamental Structure–Property Relationships

    Fabian Markl, Ingo Braun, Emanuel Smarsly, Uli Lemmer, Norman Mechau, Gerardo Hernandez-Sosa, and Uwe H. F. Bunz 
  2. ACS Applied Materials & Interfaces, vol. 6, no. 9, pp. 6616–22, May 2014.
    Investigation of Solution-Processed Ultrathin Electron Injection Layers for Organic Light-Emitting Diodes

    Sebastian Stolz, Michael Scherer, Eric Mankel, Robert Lovrinčić, Janusz Schinke, Wolfgang Kowalsky, Wolfram Jaegermann, Uli Lemmer, Norman Mechau, and Gerardo Hernandez-Sosa 
  3. Advanced Materials, vol. 26, no. 20, pp. 3235–3240, May 2014.
    The Compromises of Printing Organic Electronics: A Case Study of Gravure-Printed Light-Emitting Electrochemical Cells
    Gerardo Hernandez-Sosa, Serpil Tekoglu, Sebastian Stolz, Ralph Eckstein, Claudia Teusch, Jannik Trapp, Uni Lemmer, Manuel Hamburger, and Norman Mechau 
  4. Organic Electronics, vol. 15, no. 3, pp. 829–834, Mar. 2014.
    Modelling and simulation of gate leakage currents of solution-processed OTFT
    Stefan Hengen, Milan Alt, Gerardo Hernandez-Sosa, Jürgen Giehl, Uli Lemmer, and Norman Mechau 
  5. Organic Electronics, vol. 14, no. 12, pp. 3493–3499, Dec. 2013.
    Gravure printed flexible small-molecule organic light emitting diodes
    Serpil Tekoglu, Gerardo Hernandez-Sosa, Edgar Kluge, Uli Lemmer, and Norman Mechau 
  6. Organic Electronics, vol. 14, no. 9, pp. 2223–2227, Sep. 2013.
    The role of the polymer solid electrolyte molecular weight in light-emitting electrochemical cells

    Gerardo Hernandez-Sosa, Ralph Eckstein, Serpil Tekoglu, Tobias Becker, Florian Mathies, Uli Lemmer, and Norman Mechau
  7. Advanced Functional Materials, vol. 23, no. 25, pp. 3164–3171, Jul. 2013.
    Rheological and drying considerations for uniformly gravure-printed layers: towards large-area flexible organic light-emitting diodes

    Gerardo Hernandez-Sosa, Nils Bornemann, Ingo Ringle, Michaela Agari, Edgar Doersam, Norman Mechau, and Uli Lemmer 
  8. Applied Physics Express, vol. 5, no. 7, p. 72101, Jul. 2012.
    Ink-Jet-Printed Organic Semiconductor Distributed Feedback Laser

    Xin Liu, Sönke Klinkhammer, Kai Sudau, Norman Mechau, Christoph Vannahme, Johannes Kaschke, Timo Mappes, Martin Wegener, and Uli Lemmer