Organic Photovoltaics: relating structure to the photo-physical properties

Organic photovoltaic (OPV) devices are gaining increasing attention due to their high potential for achieving high power conversion efficiencies with a low cost per Watt ratios. The central concept in OPV devices is the utilization of photoactive layers of bulk heterojunctions. These are layers comprising polymeric electron donors mixed with fullerene derivatives that act as electron acceptors that phase separate forming networks. Exciton dissociation and charge photogeneration in the presence of such networks produced power conversion efficiencies (PCE) of up to 10% under sunlight. Inherent to the design of optimal bulk heterojunctions is the control over the relevant donor/acceptor length scale and overall blend morphology. Despite the range of applications there is little knowledge on how the blend morphology and the organization within the different phases affect the photo-physical properties.

 

Collaborators: P. E. Keivanidis (IIT, Milan)

Recent  publications (2011-2016)

[1] P.E. Keivanidis,V. Kamm, W. Zhang, G. Floudas, F. Laquai, I. McCulloch, D.D.C. Bradley, J. Nelson

“Correlating Emissive Non-Geminate Charge Recombination with Photocurrent Generation Efficiency in Polymer/Perylene Diimide Organic Photovoltaic Blend Films”,

 Adv. Funct. Mater. 22, 2318, 2012.

[2] Y. Zheng, H. Zhou, D. Liu, G. Floudas, M. Wagner, K. Koynov, M. Metzger, H.-J. Butt, T. Ikeda

“Thiophene Supramolecular Nanosheets”,

 Angewandte Chemie Int. Ed. 52, 4845-4848, 2013.

[3] T. Ye , R. Singh , H.-J. Butt , G. Floudas, P. E. Keivanidis

“Effect of local and global structural order on the performance of perylene diimide excimeric solar cells”

ACS Applied Materials & Interfaces, 5, 11844, 2013.

[4] E. Aluicio-Sarduy, R. Singh, Z. Kan, T.Ye, A. Baidak, A. Calloni, G. Berti­, L. Duò­, A. Iosifidis, S. Beaupré, M. Leclerc, H.-J. Butt, G. Floudas, P. E. Keivanidis  

“Elucidating the impact of structural order and device architecture on the performance of perylene diimide solar cells”

ACS Applied Materials & Interfaces 7, 8687-8698, 2015.

[5] R. Singh, R. Shivanna, A. Iosifidis, H.-J. Butt, G. Floudas, K. S. Narayan, P. E. Keivanidis

“Charge versus Energy Transfer Effects in High-Performance Perylene-diimide Photovoltaic Blend Films”

ACS Applied Materials & Interfaces 7, 24876-24886, 2015.