Maxim Pshenichnikov: Ultrafast Spectroscopy of Organic Photovoltaics Materials
|Wanneer:||wo 15-02-2017 11:15 - 12:15|
Bulk-heterojunction organic solar cells attract much interest as one of renewable energy source. To gain insights on how to design more efficient devices, fundamental understanding is required of the crucial first steps in photon-to-charge conversion that occurs at timescales from 100 fs to ns's. Along this way, ultrafast spectroscopy offers a number of exciting opportunities. In this presentation, I will demonstrate how ultrafast spectroscopy is used to obtain important information on initial charge generation and separation in organic photovoltaics blends. I will focus on the following issues:
(i) Efficiency of the electron transfer followed photon absorption ;
(ii) Optimization of composition of the bulk heterojunction ;
(iii) Retrieval of morphology of the bulk heterojunction .
While understanding of the first two processes provides important feedback to chemical synthesis and device engineers, the latter allows for morphology characterization in functional devices.
 O.V. Kozlov, H.D. de Gier, V.G. Pavelyev, P.H.M. van Loosdrecht, R.W.A. Havenith, J.C. Hummelen, M.S. Pshenichnikov, "Ultrafast electron and hole transfer in bulk heterojunctions of low-bandgap polymers", Organic Photonics and Photovoltaics 4, 24-34 (2016)
 O.V.Kozlov, Y.N.Luponosov, S.A.Ponomarenko, D.Yu.Paraschuk, Y.Olivier, D.Beljonne, J.Cornil, N. Kausch-Busies, M.S. Pshenichnikov, "Ultrafast charge dynamics in novel star-shaped conjugated molecules for organic photovoltaics" (cover page), Advanced Energy Materials, 5(7), pp. 1401657 (2015)
 O.V. Kozlov, F. de Haan, R.A. Kerner, B.P. Rand, D. Cheyns, and M.S. Pshenichnikov, "Real-time tracking of singlet exciton diffusion in organic semiconductors", Phys. Rev. Lett. 116, 057402 (2016); A. Serbenta, O.V. Kozlov, Giuseppe Portale, P.H.M. van Loosdrecht, and M.S. Pshenichnikov, "Bulk heterojunction morphology of polymer:fullerene blends revealed by ultrafast spectroscopy", Scientific Reports (Nature) 6, 36236 (2016)