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Enhancing the Efficiency of Organic Photovoltaics by a Photoactive Molecular Mediator (Solar RRL 1∕2018)
Author(s) -
Yang Bin,
Kolaczkowski Matthew A.,
Brady Michael A.,
Keum Jong K.,
Browning James F.,
Chen Teresa L.,
Liu Yi
Publication year - 2018
Publication title -
solar rrl
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.544
H-Index - 37
ISSN - 2367-198X
DOI - 10.1002/solr.201770149
Subject(s) - photoactive layer , organic solar cell , materials science , polymer solar cell , energy conversion efficiency , photovoltaics , active layer , phase (matter) , nanotechnology , morphology (biology) , chemical engineering , conjugated system , layer (electronics) , polymer , chemistry , optoelectronics , photovoltaic system , organic chemistry , composite material , engineering , biology , ecology , thin film transistor , genetics
In the search for high efficiency organic solar cells, additives often play an important role in improving the film morphology. The vast majority of the currently used additives are liquids that, while often effective, evaporate or migrate over time lowering the stability of the device. Herein, Liu et al. (article No. 1700208 ) report a solid photoactive molecular mediator, namely N(BAI) 3 , that could be employed to replace the liquid additives to tune the morphology of bulk heterojunction films for improved device performance. The N(BAI) 3 mediator not only resides in the active films to fine tune the phase morphology, but also contributes to the additional absorption of the active films, leading to ∼ 11% enhancement of power conversion efficiency of P3HT:PC 60 BM devices. In‐depth studies on the nanoscale morphologies using X‐ray and neutron scattering techniques suggest that the use of 1 wt% N(BAI) 3 effectively tunes the packing of P3HT, presumably through balanced Π‐interactions endowed by its large conjugated Π surface, and promote the formation of a PC 60 BM‐rich top interfacial layer. These findings open up a new way to tailor the phase morphology by photoactive molecular mediators in organic photovoltaics.