2024-03-29T09:08:32Zhttps://repositori.uji.es/oai/requestoai:repositori.uji.es:10234/1512132024-01-09T10:08:04Zcom_10234_2507com_10234_9col_10234_6973
00925njm 22002777a 4500
dc
Guerrero, Antonio
author
Pfannmöller, Martin
author
Kovalenko, Alexander
author
Ripollés Sanchis, Teresa
author
Heidari, Hamed
author
Bals, Sara
author
Kaufmann, Louis-Dominique
author
Bisquert, Juan
author
Garcia-Belmonte, Germà
author
2015
Organic photovoltaic (OPV) devices are on the verge of commercialization being long-term
stability a key challenge. Morphology evolution during lifetime has been suggested to be
one of the main pathways accounting for performance degradation. There is however a lack
of certainty on how specifically the morphology evolution relates to individual electrical
parameters on operating devices. In this work a case study is created based on a thermodynamically
unstable organic active layer which is monitored over a period of one year
under non-accelerated degradation conditions. The morphology evolution is revealed by
compositional analysis of ultrathin cross-sections using nanoscale imaging in scanning
transmission electron microscopy (STEM) coupled with electron energy-loss spectroscopy
(EELS). Additionally, devices are electrically monitored in real-time using the non-destructive
electrical techniques capacitance–voltage (C–V) and Impedance Spectroscopy (IS). By
comparison of imaging and electrical techniques the relationship between nanoscale morphology
and individual electrical parameters of device operation can be conclusively discerned.
It is ultimately observed how the change in the cathode contact properties
occurring after the migration of fullerene molecules explains the improvement in the overall
device performance.
1566-1199
1878-5530
http://hdl.handle.net/10234/151213
http://dx.doi.org/10.1016/j.orgel.2014.11.007
Organic photovoltaics
degradation
shelf life
morphology evolution
contact selectivity
low-energy-loss electron spectroscopic imaging
Nanoscale mapping by electron energy-loss spectroscopy reveals evolution of organic solar cell contact selectivity