Lecture Jorge Piris
|12 February 2009||FWN-Building 5116.0124, Nijenborgh 4, 9747 AG, Groningen|
|Speaker:||Dr. Jorge Piris|
|Affiliation:||Technische Natuurkunde, TU Delft|
|Title:||Photoexcitations and Charge Generation Dynamics in Polymers for Organic Photovoltaics Studied by Ultrafast Transient Absorption Spectroscopy|
|Date:||Thu Feb 12, 2009|
|Telephone:||+31 50 363 4159|
The field of organic photovoltaics (OPV) has seen tremendous growth in the past few years, driven by growing needs for affordable and pollution-free conversion of solar energy to electricity. OPV devices typically consist of a light absorbing polymer and an electron accepting fullerene derivative. Light absorption by the polymer leads to excitation of an lectron that is strongly bound to the remaining positive charge (hole). This so-called exciton has to diffuse to the interface between the polymer and the fullerene where it dissociates to a hole in the polymer and an electron in the fullerene. Using this approach OPV devices based on polymer-fullerene blends have been certified to 4.8% power conversion efficiency. Nevertheless, the actual mechanism leading to photogeneration of charge carriers in these materials is an issue of intense debate.
Our work aims at elucidating the mechanism of charge generation in blends of a polymer poly(3-hexylthiophene) (P3HT) and the fullerene [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). We have studied the processes following photo-excitation by means of transient absorption spectroscopy on time scales as short as 100 femtoseconds.
J. Piris, T.E. Dykstra, M.T. Trinh, J.M. Schins andL.D.A. Siebbeles
|Last modified:||22 October 2012 2.30 p.m.|