Journal
CHEMISTRY OF MATERIALS
Volume 21, Issue 22, Pages 5508-5518Publisher
AMER CHEMICAL SOC
DOI: 10.1021/cm902531d
Keywords
-
Funding
- BASF SE [NSC-095-SAF-1-564-626-TMS]
- NSF-DMR
- Sloan Research Fellowship
Ask authors/readers for more resources
The effects of the interplay between energetic and kinetic factors on the air stability of n-channel organic thin-film transistors (OTFTs) were studied using two perylene diimide (PDI) compounds with distinctly different lowest unoccupied molecular orbital (LUMO) levels. On the basis of the empirical energy level windows, one compound (N,N'-bis(2,2,3,3,4,4,5,5,5-nonafluoropentyl)-3,4:9,10-tetracarboxylic acid diimide (PDI-F): -3.84 eV) is at the onset region for air stability, whereas the other (N,N'-bis(cyclohexyl)-1,7-dicyano-perylene-3,4:9,10-tetracarboxylic acid diimide (PDI-CN2): -4.33 eV) is in the air-stable region. Charge-transport behaviors under an inert atmosphere and in air were investigated as a function of active layer thickness. Charge transport in air was greatly affected by the active layer thickness for both compounds, an effect that has been overlooked so far. The ambient stability of the air-unstable PDI-F TFTs increased significantly for thicknesses over similar to 10 monolayers (ML). Surprisingly, the previously considered air-stable PDI-CN2 TFTs were not stable in air if the active layer thickness was less than similar to 4 ML. The molecular packing and orientation of the PDI thin Films were investigated using grazing incidence X-ray diffraction (GIXD) and near-edge X-ray absorption fine structure (NEXAFS). We found that the minimum thickness required for air stability is closely related to the LUMO level, film morphology, and film growth mode.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available