Morphology of organic electronic materials imaged via electron tomography

Abstract

SummaryOrganic electronic materials and nanostructures have been studied with the use of electron tomography. Nanostructured materials including contrast enhancing features have been studied and double tilt data collection has been employed to improve reconstructions. Tomography reconstructions of active layers of organic solar cells, where various preparation techniques have been used, have been analysed and compared to device behaviour. Small changes in preparation procedures may lead to large differences in morphology and device performance, and the results also indicate a complex relation between these.

Characterisation of charge conduction networks in poly(3-hexylthiophene)/polystyrene blends using noise spectroscopy

“…Of course, such network information is available through other techniques, such as c-AFM, 36 scanning transmission X-ray microscopy (STXM) 37 and electron tomography. 38 Our results suggest that 1/f noise can be used to examine the network from the viewpoint of the charges, since the form of the network the charges travel through is revealed by k. However, it should be noted that in OPV blends both networks are semiconducting, as opposed to just one here. The use of noise spectroscopy in OPV blends to probe morphology will be examined in further publications.…”

Bulk Heterojunction Nanomorphology of Fluorenyl Hexa-peri-hexabenzocoronene–Fullerene Blend Films

“…Several examples of 3D reconstructions of the nanomorphology of OSC absorber layers can be found in the literature. [15][16][17][18] In our previous studies, FHBC was employed as electron donor material in BHJ OSCs. 19 Hexaperi-hexabenzocoronene (HBC) is a discotic polycyclic aromatic hydrocarbon with well-known liquid crystalline properties as a result of strong − intermolecular association between the molecules.…”

“…This limitation can be overcome by TEM tomography which facilitates the reconstruction of the three-dimensional (3D) sample structure. Several examples of 3D reconstructions of the nanomorphology of OSC absorber layers can be found in the literature. − …”

Intermixing Effect on Electronic Structures of TQ1:PC71BM Bulk Heterojunction in Organic Photovoltaics

“…It is noted that the BHJ with the very low PC 71 BM concentration (5:1 and 10:1) have a slightly modified work function compared to neat TQ1 films, suggesting fine intermixing even at these concentrations. The work function evolution of the BHJ is close to flat from the donor‐rich to acceptor‐rich in the wide range of 1:5 to 5:1, even 10:1, suggesting fine intermixing in good agreement with TQ1:PC 71 BM nanoscale morphology imaged via electron tomography . This is unlike the case of rr‐P3HT:PC 61 BM displayed in Figure d as a reference .…”