Charge-transfer states in DBP-C70 organic solar cells:sensitive external quantum efficiency (sEQE) and morphological studies

Publikation: Konferencebidrag uden forlag/tidsskriftPosterForskningpeer review


  • Golnaz Sherafatipour

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Organic photovoltaic (OPV) is an emerging economically competitive photovoltaic technology that has advantages over conventional inorganic PV technology including low fabrication cost, lightweight, semi-transparency and mechanical flexibility1. Despite these advantages, OPVs have comparably low power conversion efficiencies and rather short lifetimes, which are the most critical factors hampering their application. In order to overcome these barriers and close the gap between laboratory achievements and industrial scale requirements, a detailed understanding of the device degradation mechanism is required. Charge transfer (CT) states, representing intermediate states between exciton dissociation and recombination at donor-acceptor interface, play hereby a crucial role. In this work, we study CT states in DBP-C70 based organic solar cells as a less studied case for inverted and conventional structures. Results from sensitive external quantum efficiency (sEQE) measurements show an unexpected difference in charge transfer state energies for each of the two common structures. Moreover, we observe different values for the reorganization energy, which determines the energy loss upon deformation of the molecule during charging. These results suggest morphological sensitivity of the D-A interface, depending on the deposition sequence, which is investigated amongst others by means of atomic force microscopy studies. These investigations are followed by aging the devices and detecting the probable changes in the previously obtained parameters.
Publikationsdatonov. 2016
StatusUdgivet - nov. 2016
BegivenhedInternational Summit on OPV Stability - Konzerthaus Freiburg, Freiburg, Tyskland
Varighed: 12 okt. 201614 okt. 2016
Konferencens nummer: 9


KonferenceInternational Summit on OPV Stability
LokationKonzerthaus Freiburg