TRITON · Controlling Wavefunction Overlap for Triplet Energy Transfer in Organic/Nanocrystal Quantum Dots Hybrids
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2019-04-01 → 2021-03-31
- EU contribution
- €224,934
- Participants
- 1
- Scheme
- MSCA-IF-EF-ST
Lines connect the coordinator with its partners.
Results in brief
Controlling Wavefunction Overlap for Triplet Energy Transfer in Organic/Nanocrystal Quantum Dots Hybrids
This project aims to develop the fundamental science for a new platform for optoelectronics and photochemistry based on coupling triplet excitons from organic semiconductors (OSCs) to semiconductor quantum dots (QDs) such as lead chalcogenides. The knowledge gained will overcome many current limitations of triplet exciton coupling from organic to inorganic semiconductors for emerging optoelectronic applications. This targets for this project are of great importance to society, as many emerging technologies under development are based on OSCs and QDs, and recently the hybrid of them are found to have some very unique properties that can potentially overcome many problems that the materials possess standalone. The findings from this project would provide guidance in the field of solar energy conversion, lighting, bioimaging and other optoelectronic devices. The candidate and the host group aim to conduct systematic studies on the factors that govern triplet energy transfer (TET) within the OSCs/QDs hybrid systems. Throughout the project, the candidate has identified some key factors dominates the TET efficiency, and developed a series of chemical processes that enable one to control these factors, in order to fabricate the materials with the targeted properties. It is concluded that very delicate control is needed to fabricate a hybrid material with efficiency TET transfer. Some of the important factors for TET can be well controlled, while some others are more difficult. For example, it is relatively simple to reduce the distance between the QDs and OSCs, which can lead to ~100% TET efficiency, however when doing so the distance between the QDs would also decrease, leading to quenching of the photoluminescence and hence lower overall emission yield. Such kind of problems are likely the next main targets to be tackled in the future, in order to fabricate materials with high overall energy conversion efficiency.
Data: CORDIS, © European Union
Project objective
The generation, control and transfer of triplet excitons in molecular and hybrid systems is of great interest for optoelectronic applications such as light emission, singlet fission, up/down-conversion and photovoltaics. While coupling triplet excitons from inorganic QDs to organic molecules has been well demonstrated, the reverse process, the transfer of triplets from organic semiconductors to QDs is much more challenging and the underlying reasons are still unclear to the field. Recently, the host group has demonstrated that it is possible to transfer triplet excitons from molecular acenes to emissive nanocrystal quantum dots (QDs). This allows the direct conversion of dark triplet excitons to photons in the hybrids. As triplets generation yield through singlet fission in acene molecules can be up to 200%, this discovery opens a new avenue for highly efficient down-conversion. However, the exact factors that govern the transfer, especially the role of interfaces between the two components, remains unknown. The project will build on the host group’s discovery to develop the fundamental science of this new hybrids platform for optoelectronics. Specifically, we will develop a series of highly controlled solution/solid phase systems, where the interfacial conditions of the hybrid will be intentionally modified. The surface ligands, passivation, energy states of the QDs and the distance to the molecules will be precisely controlled. The molecules will also be covalently attached to the QD surface by a range of functional groups. These systems will be studied with steady-state and time-resolved spectroscopies with the aim of elucidating the underlying mechanism controlling the wavefunction overlap and triplet exciton transfer in the hybrids. We will also conduct proof of concept experiments to demonstrate the use of the optimised hybrid materials for down-convertor. These fundamental investigations will open up new possibilities for down-conversion and optoelectronics.
Original text from CORDIS.
Participants
- THE CHANCELLOR MASTERS AND SCHOLARS OF THE UNIVERSITY OF CAMBRIDGE · CAMBRIDGECoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union