Andrey Kadashchuk (Author), Fei Tong (Author), Egon Pavlica (Author), Gvido Bratina (Author)

Abstract

Charge-carrier mobility has been investigated by time-of-flight (TOF) transient photocurrent in a lateral transport con- figuration in highly crystalline thin films of 2,7-dioctyl[1]benzothieno [3,2-b][1] benzothiophene (C8-BTBT) grown by a zone-casting alignment technique. High TOF mobility has been revealed that it is consistent with the delocalized nature of the charge transport in this material, yet it featured a positive temperature dependence at T ≥ 295 K. Moreover, the mobility was surprisingly found to decrease with electric field in the high-temperature region. These observations are not compat- ible with the conventional band-transport mechanism. We have elaborated an analytic model based on effective-medium approximation to rationalize the puzzling findings. The model considers the delocalized charge transport within the energy landscape formed by long-range transport band-edge variations in imperfect organic crystalline materials and accounts for the field-dependent effective dimensionality of charge transport percolative paths. The results of the model calculations are found to be in good agreement with experimental data.

Keywords

time of flight;organic semiconductors;single crystals;

Data

Language: English
Year of publishing:
Typology: 1.01 - Original Scientific Article
Organization: UNG - University of Nova Gorica
UDC: 53
COBISS: 5147899 Link will open in a new window
ISSN: 1336-9075
Views: 4178
Downloads: 0
Average score: 0 (0 votes)
Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

URN: URN:SI:UNG
Type (COBISS): Not categorized
Pages: str. 1685-1695
Volume: ǂVol. ǂ72
Issue: ǂiss. ǂ7
Chronology: 2018
DOI: 10.1007/s11696-018-0483-x
ID: 10930616