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Influence of Meso and Nanoscale Structure on the Properties of Highly Efficient Small Molecule Solar Cells
Author(s) -
Moench Tobias,
Friederich Pascal,
Holzmueller Felix,
Rutkowski Bogdan,
Benduhn Johannes,
Strunk Timo,
Koerner Christian,
Vandewal Koen,
CzyrskaFilemonowicz Aleksandra,
Wenzel Wolfgang,
Leo Karl
Publication year - 2016
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201501280
Subject(s) - materials science , organic solar cell , nanoscopic scale , quantum efficiency , chemical physics , transmission electron microscopy , scanning transmission electron microscopy , heterojunction , spectroscopy , nanotechnology , polymer solar cell , solar cell , molecule , optoelectronics , polymer , composite material , physics , quantum mechanics
The nanoscale morphology of the bulk heterojunction absorber layer in an organic solar cell (OSC) is of key importance for its efficiency. The morphology of high performance vacuum‐processed, small molecule OSCs based on oligothiophene derivatives (DCV5T‐Me) blended with C 60 on various length scales is studied. The analytical electron microscopic techniques such as scanning transmission electron microscopy, energy dispersive X‐ray spectroscopy, highly sensitive external quantum efficiency measurements, and meso and nanoscale simulations are employed. Unique insights into the relation between processing, morphology, and efficiency of the final devices are obtained. It is shown that the connectivity of the oligothiophene‐C 60 network is independent of the material domain size. The decisive quantity controlling the internal quantum efficiency is the energetic disorder induced by material mixing, strongly limiting charge and exciton transport in the OSCs.