|Project:||ESR-8: PhD at University of Mons, Belgium|
|Topic:||Triplet migration and annihilation in organic conjugated materials|
|Researcher (ESR):||Mr. Rexiati Dilimulati|
|Supervisor:||Prof. Dr. David Beljonne|
Triplet migration and annihilation in organic conjugated materials
The experimental group from the University of Groningen had used two small push-pull molecules (SA321 and TV38) as donors and PCBM fullerene as acceptor in bulk heterojunction (BHJ) organic solar cell devices and obtained a power conversion efficiency (PCE) of 4.75% and 2.2%, respectively. The results depend on whether the active layer is formed by solution processing or vacuum deposition. The molecule SA321 has approximately two times larger lifetime and diffusion length compared to TV38 which largely affects the PCE of the solar cell.
It is not entirely understood why such similar molecules have a very different diffusion length. What factors influence the exciton diffusion length?
Morphology and/or disorder of the system have a strong influence on the exciton diffusion length. Rexiati will use Kinetic Monte Carlo (KMC) simulation to evaluate diffusion length and the other interesting parameters of the two molecules. In addition he will also use Raman and photo-absorption spectroscopy with DFT (density functional theory) and TDDFT (time-dependent density functional theory).
Rexiati was born in Hoten, China. In 2017 he received his Master`s degree in theoretical physics from the Cergy-Pontoise University, Paris, France. He is currently working as a PhD researcher at the Laboratory for Chemistry of Novel Materials in Mons, Belgium.