PROLED · Polymer Radicals as doublet emitters for Organic Light-Emitting Diodes
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2020-10-01 → 2022-09-30
- EU contribution
- €212,934
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Polymer Radicals as doublet emitters for Organic Light-Emitting Diodes
For organic emitters used in light-emitting diodes, electrical excitations generate singlet and triplet excited states in 1:3 ratio due to spin statistics. In case of fluorescent emitters, only the singlet state can decay radiatively and emit light in singlet–singlet (S1–S0) fluorescence, which means 75% of excitations are lost as dark triplets. Different strategies have been employed to harvest both singlet and triplet excitons from organic emitters, and thus increase the efficiency of light-emitting diodes. However, the challenge is that triplet–singlet (T1–S0) transition is spin forbidden. Neutral π-radicals are a completely different class of organic emitters, wherein the emission comes from spin doublet. Doublet–doublet (D1–D0) fluorescence is a totally spin allowed process enabling 100% radiative decay. Doublet fluorescence also benefits from fast emission in the nanosecond timescales, which further reduces chances for exciton quenching and improves the operational lifetime of the device. The aim of this project is to develop polymeric π-radicals as a new class of highly luminescent emitters by chemically coupling molecular radicals into conjugated polymers. This approach combines the benefits of low-cost solution-based processing of conjugated polymers and the attainable high efficiency of doublet emission from radical materials. The results of this project enable rational design of π-radicals with varied extent of conjugation spanning from small molecular radicals and biradicals to main-chain polyradicals, while providing practical tools for clean and quantitative synthesis of these radical materials. This project also adds to fundamental understanding of the emission process of π-radicals and reveals new approaches to the design highly emissive materials, which can be exploited in a wide range of organic optoelectronic applications where high yields of emissive excitons are needed.
Data: CORDIS, © European Union
Project objective
Stable neutral π-radicals can utilise up to 100% of excitons as doublet emission in organic light-emitting diodes (OLEDs), thus circumventing the limitations of traditional fluorescent (singlet) and phosphorescent (triplet) emitters. Our aim is to develop polymer radicals as a new class of highly luminescent emitters by chemically coupling stable radical molecules into suited polymer backbones. This will interconnect the benefits of low-cost solution-based processing of conjugated polymers and the attainable high efficiency of doublet emission from π-radicals. Novel polymers will be synthesized and scrutinized using a range of state-of-the-art spectroscopic techniques. The most promising polymers will be selected for OLEDs fabrication using solution-based methods. Polymer radicals exhibit simultaneously optical, electronic and magnetic properties. This will open new possibilities not only for OLEDs but also for other fields, such as photovoltaics, polymer magnetics, lightweight batteries and supercapacitors, spintronics and antistatic coatings for consumer electronics.
Original text from CORDIS.
Participants
- THE CHANCELLOR MASTERS AND SCHOLARS OF THE UNIVERSITY OF CAMBRIDGE · CAMBRIDGECoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union