Open-circuit voltage of organic solar cells: interfacial roughness makes the difference

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

Abstract

Organic photovoltaics (PV) is an energy-harvesting technology that offers many advantages, such as flexibility, low weight and cost, as well as environmentally benign materials and manufacturing techniques. Despite growth of power conversion efficiencies to around 19 % in the last years, organic PVs still lag behind inorganic PV technologies, mainly due to high losses in open-circuit voltage. Understanding and improving open circuit voltage in organic solar cells is challenging, as it is controlled by the properties of a donor-acceptor interface where the optical excitations are separated into charge carriers. Here, we provide an electrostatic model of a rough donor-acceptor interface and test it experimentally on small molecule PV materials systems. The model provides concise relationships between the open-circuit voltage, photovoltaic gap, charge-transfer state energy, and interfacial morphology. In particular, we show that the electrostatic bias generated across the interface reduces the photovoltaic gap. This negative influence on open-circuit voltage can, however, be circumvented by adjusting the morphology of the donor-acceptor interface.

Details

OriginalspracheEnglisch
Aufsatznummer307
FachzeitschriftCommunications Physics
Jahrgang5
Ausgabenummer1
PublikationsstatusVeröffentlicht - Dez. 2022
Peer-Review-StatusJa

Schlagworte

Ziele für nachhaltige Entwicklung

ASJC Scopus Sachgebiete

Bibliotheksschlagworte