International TADF Symposium in Frankfurt is upcoming

On Thursday, September 7, 2017, the International TADF Symposium (organized by cynora GmbH) will take place in Frankfurt. It will be a packed one-day event with a tight focus on OLEDs based on thermally activated delayed fluorescence (TADF). The event will bring together leading industry and academia to share new results and discuss upcoming developments. You can find all the details about speakers and program on the events webpage. It is definitely a very good opportunity to get in touch with the people working on this exciting material development.

TADF paper featured in Advanced Science News

Our recent paper together with our colleagues at the Leibniz Institute of Polymer Research Dresden (IPF), is featured in Advanced Science News. This work discusses a novel way to achieve thermally activated delayed fluorescence in polymers through an extension of the HOMO conjugation, which ultimately leads to a smaller splitting between singlet and triplet excited charge transfer states. The paper can be found here: Conjugation-Induced Thermally Activated Delayed Fluorescence (TADF): From Conventional Non-TADF Units to TADF-Active Polymers.

DPG Frühjahrstagung Dresden 2017 starts tomorrow

The DPG-Frühjahrstagung der Sektion Kondensierte Materie (SKM) will take place from March 19 – 24 in Dresden this year. Below, you find a list of our group’s contributions throughout the week. We are looking forward to an exciting and fruitful week of discussions and exchange. See you there. (There is even a hashtag for the event: #DPGDD17)

Mo, 11:00 CPP 7.1 Two-color warm white hybrid OLEDs from thermally activated delayed fluorescence — Ludwig Popp, Paul Kleine, Reinhard Scholz, Ramunas Lygaitis, Olaf Zeika, Axel Fischer, Simone Lenk, and Sebastian Reineke
Mo, 11:15 CPP 7.2 Conjugation induced thermally activated delayed fluorescence — Paul Kleine, Qiang Wei, Yevhen Karpov, Xianping Qiu, Hartmut Komber, Karin Sahre, Anton Kiriy, Ramunas Lygaitis, Simone Lenk, Brigitte Voit, and Sebastian Reineke
Mo, 12:15 CPP 7.6 Ultrathin metal electrode for bottom-emitting OLEDs on buckled substrates — Yungui Li, Toni Bärschneider, Paul-Anton Will, Yuan Liu, Simone Lenk, and Sebastian Reineke
Di, 15:45 CPP 26.8 Absolute optical sensor based on biluminescence — Caterin Salas Redondo and Sebastian Reineke
Mi, 18:30 CPP 50.13 controlling excitons in exciplex host systems for efficient white OLEDs — Yuan Liu, Simone Lenk, Karl Leo, and Sebastian Reineke
Mi, 18:30 CPP 50.19 Synthesis and characterisation of the new emitters for OLED applications — Ramunas Lygaitis, Olaf Zeika, Reinhard Scholz, Ludwig Popp, Paul Kleine, Simone Lenk, and Sebastian Reineke
Mi, 13:00 DS 29.14 Influence of radiative efficiency and dipole orientation on optimal layer thicknesses of monochrome OLEDs for maximum EQE — Paul-Anton Will, Cornelius Fuchs, Reinhard Scholz, Simone Lenk, and Sebastian Reineke
Mi, 15:15 DS 34.2 Determination of the molecular orientation in absorptive organic thin films — Christian Hänisch, Simone Lenk, and Sebastian Reineke
Mi, 09:30 HL 52.1 Full Range Electrothermal Modeling of Organic Light-emitting Diodes — Axel Fischer, Koen Vandewal, Simone Lenk, and Sebastian Reineke
Mi, 15:00 HL 64.19 Diffuse Transmission and Reflection of Light Scattering Polymer Substrates for Organic Light-emitting Diodes — Pen Yiao Ang, Georg Marks, Abdalla Mahmoud, Axel Fischer, Simone Lenk, and Sebastian Reineke

Ryutaro Komatsu (see below) is currently visiting our group as part of an ongoing exchange program between TU Dresden and Universities from Japan. He is a PhD candidate of Prof. Junji Kido from Yamagata University – good chance to see some of their recent work.

Mi, 18:30 CPP 50.14 Efficient Deep-blue Pyridimidine-based TADF Emitters Using a Highly Twisted Molecular Skeleton — •Ryutaro Komatsu, Tatsuya Ohsawa, Hisahiro Sasabe, Kohei Nakao, Yuya Hayasaka, and Junji Kido


New paper: Conjugation-Induced Thermally Activated Delayed Fluorescence (TADF): From Conventional Non-TADF Units to TADF-Active Polymers

In a recent collaboration with our colleagues at the Leibniz Institute of Polymer Research Dresden (IPF), we have developed polymers that show thermally activated delayed fluorescence (TADF) properties with high efficiency. This work has now been published in Advanced Functional Materials under the title: Conjugation-Induced Thermally Activated Delayed Fluorescence (TADF): From Conventional Non-TADF Units to TADF-Active Polymers. Interestingly, the monomer building block does not show TADF but rather only phosphorescence. Hence, the TADF property is induced as a consequence of increased conjugation during polymer formation. Ultimately, the singlet-triplet splitting is reduced in the polymer to allow for TADF. The emitter shows sky-blue emission with roughly 70% PLQY. This report includes the synthesis of the monomer and polymer materials, quantum chemical calculations and a detailed photo-physical characterization.

Session preview: Excitons in Organic and Hybrid Systems I

This announcement comes in parallel with the start of the session Excitons in Organic and Hybrid Systems I of our Symposium EP1, which began 5 minutes ago. Today we are looking in more detail on processes connected with excitons in organic and hybrid systems. We will see sophisticated techniques, modeling, etc.

Here are some keywords that we will come across during the morning program:

  • Nanoscale exciton migration
  • QM/MM simulation of TADF materials
  • Exciton migration in TADF materials
  • Exciton transport in colloidal QDs
  • Spin oscillations
  • Single molecule look on TADF
  • Spatial confinement of triplet excitons in rubrene
  • Exciton processes in OLEDs

Our invitees are Naomi Ginsberg, William Tisdale, John Lupton, and Grayson Ingram.

Preview: Two sessions on Wednesday

Tomorrow, Wednesday March 30, we have two sessions at our Symposium EP1: Organic Excitonic Systems and Devices.

EP1.2: Organic Emitters

The morning focus will be on the emitters itself, where we will here recent progress on various molecular concepts for high performance luminescence. This will include the fundamental studies that excel our current understanding of these emitters. Some things that we will see:

  • Design rules for TADF emitters
  • Crystalline OLED emission layers for nearly perfect emitter alignment
  • Investigation of exciplex emission (electric field dependence and charge separation)
  • Nickel-Tetra-Mesityl-Porphoyrin photophysics
  • Platinum complexes for high efficiency, color pure blue OLEDs
  • Control of molecular orientation
  • TADF emitters for LECs and OLEDs
  • Biluminescence for optical sensing
  • Photophysics of H- and J-aggregates

Our invited speakers of the morning are: Andrew Monkman, Wolfgang Brütting, and Frank Würthner.

EP1.3: Organic Lasers

In the afternoon we switch gears – Its laser time. With the basis of the laser tutorial we had on Monday, we should be all set for some interesting contributions related to laser physics with organics. Important: Due to a serious illness of one of our speakers, the program of the first part of the EP1.3 session has been updated. We will start at 2:00pm rather than the originally planned time of 1:30pm. Please refer to the online program for the latest updates!

Here are some details to the post-lunch session:

  • Condensate physics with organic polaritons
  • Tunable, narrow line width solid-state lasers
  • LED-pumped organic lasers (planar integration) based on luminescent concentration
  • Self-assembled colloidal lasers
  • Low threshold up-converted laser
  • Strong coupling in organic microcavities
  • Solvent nano imprint lithography of polymer lasers
  • Photoluminescence enhancement in nano cavities

Our afternoon invited speakers are: Stéphane Kéna-Cohen and Alexander J. Kuehne.

Again, a lot of cool and interesting things to look forward to. See you tomorrow!

Session Preview: EP1.1 – Organic Light-Emitting Devices

Tomorrow, Tuesday March 29, we start out with the first Session of our Symposium EP1 Organic Excitonic Systems and Devices. The session runs under the title Organic Light-Emitting Devices (OLEDs). So clearly, we are looking to a collection of recent progress on the OLED technology, where the optimization of efficiency is in the central focus. Here are some keywords that will represent the content of tomorrow:

  • Enhanced emission of OLEDs
  • Bright NIR OLEDs based on high mobility polymers
  • Intrinsic degradation mechanisms in UV and blue OLEDs
  • Increased stability of TADF OLEDs
  • 100% triplet harvesting in fluorescent OLEDs
  • Blue phosphorescent OLEDs
  • Absence of triplet up-conversion in anthracene based emitters
  • Afterglow OLEDs (a demonstration of biluminescence in OLEDs)
  • Origin and control of emitter orientation in OLEDs

Our invited speakers for this session are: Mark Thompson, Stephen R. Forrest, and Jang-Joo Kim.