Dresden 2020 – wissenschaftliches Programm

Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

SYSD: Symposium SKM Dissertation Prize 2020

SYSD 1: SKM Dissertation Prize

SYSD 1.3: Hauptvortrag

Montag, 16. März 2020, 10:20–10:45, HSZ 02

Non-radiative voltage losses in organic solar cells — •Johannes Benduhn — Institut für Angewandte Physik, Technische Universität Dresden, Dresden, Germany

Global warming is one of the biggest challenges of this century and therefore new, green and cost-efficient technologies are needed to supply the electricity of tomorrow. In this regard, organic solar cells (OSCs) offer several unique advantages as they can be semi-transparent, lightweight, flexible, and cost-efficiently produced and therefore allow for an easy integration into surfaces of already existing buildings and mobile applications. A widespread use of this technology however requires an increase in the power conversion efficiency, which is currently still lower than that of established inorganic photovoltaic technologies. The main reason is that the voltage produced under illumination is low as compared to the optical gap of the absorber molecules, indicating high energy losses per absorbed photon.

In this work, I trace the origin of these losses back to large, non-radiative recombination losses mediated by molecular vibrations and electron-phonon coupling. With this understanding, reductions in non-radiative decay rates by a factor of 1.000 as compared to the current state-of-the-art OSCs are achieved, through a rational choice of molecules with appropriate energy levels and optical gaps. The resulting device does not only exhibit good photovoltaic properties, but also acts as a rather efficient light emitting device; resolving a long-believed paradigm that good emission and charge-carrier generation are mutually exclusive properties in organic optoelectronic devices.