Interface dipole : effects on threshold voltage and mobility for both amorphous and poly-crystalline organic field effect transistors

C. Celle (1) , C. Suspène (1) , M. Ternisien (2) , S. Lenfant (2) , David Guérin (2) , K. Smaali (2) , K. Lmimouni (2) , J.P. Simonato (1) , Dominique Vuillaume (2)

1 DTNM - Département des Technologies des Nouveaux Matériaux (Ex Département des Technologies des NanoMatériaux)
2 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520

We report a detailed comparison on the role of a self-assembled monolayer (SAM) of dipolar molecules on the threshold voltage and charge carrier mobility of organic field-effect transistor (OFET) made of both amorphous and polycrystalline organic semiconductors. We show that the same relationship between the threshold voltage and the dipole-induced charges in the SAM holds when both types of devices are fabricated on strictly identical base substrates. Charge carrier mobilities, almost constant for amorphous OFET, are not affected by the dipole in the SAMs, while for polycrystalline OFET (pentacene) the large variation of charge carrier mobilities is related to change in the organic film structure (mostly grain size).

Mots clés: organic transistor; organic monolayer; dipole

Domaines: Sciences de l'ingénieur [physics]

C. Celle, C. Suspène, M. Ternisien, S. Lenfant, David Guérin, et al.. Interface dipole : effects on threshold voltage and mobility for both amorphous and poly-crystalline organic field effect transistors. Organic Electronics, 2014, 15, pp.729-737. ⟨10.1016/j.orgel.2014.01.003⟩. ⟨hal-00939052⟩