Project "Understanding the Origin of Magnetic Field Effects in Organic Electronic Devices" (ModISC)

Organic Electronics (OE) is currently a very exciting and dynamic research field. With applications such as OLED commonly used in smart phones, TV screens, organic solar cells (OSC), and organic memory (OMEM). While the first generation of OLEDs integrated singlet emitters, the second involved predominantly triplet emissive materials.
Today, the third generation relies on the TADF mechanism, i.e. the interconversion of triplet to singlet states. Since the discovery of spinpolarized transport in organic semiconductors, the field of organic spintronics has attracted increasing attention from a fundamental perspective as well as a new field of potential application. One phenomenon currently presents a challenge for theoretical and experimental investigation: the so-called organic magnetoresistance (OMR), i.e., the current is influenced by an external magnetic field. We have recently reported on a prototype of a nonvolatile light-emitting OMEM that integrates a layer of dithienylethene (DTE) photochromes into an OLED. We used a DTE layer as an electrical switch within our OLED. Devices containing DTE showed an unconventional and very interesting response to magnetic fields.
The focus of this project is to unravel the origin of spin-related OMR effects in OLEDs by employing specifically designed emissive materials.
The project includes
(i) modification of the trapping landscape by adding various singlet and triplet traps to control singlet-triplet transition rates;
(ii) Light-emitting molecular switches based on DTE with varying hyper-fine interaction strength;
(iii) TADF emitters;
(iv) Cu-complexes featuring balanced dual emission as well as others.

For detailed information on the whole project follow the link to the project website:
https://www.modisc.hhu.de/