TY - JOUR
T1 - Influence of self-assembled monolayer chain length on modified gate dielectric pentacene thin-film transistors
AU - Hill, I. G.
AU - Weinert, C. M.
AU - Kreplak, L.
AU - Van Zyl, B. P.
PY - 2009/4
Y1 - 2009/4
N2 - Self-assembled monolayers are widely used to modify the gate dielectric/semiconductor interface in organic thin-film transistors. By modifying the interaction between the molecular semiconductor and the substrate, thin-film ordering and the electronic properties of the semiconducting channel can be controlled. The modified semiconductor/dielectric properties result in macroscopically observed changes in the charge-carrier mobilities, threshold voltages, subthreshold swing and transfer characteristic hysteresis. The latter two are determined by the density of charge-trapping states at the interface. Here, we investigate the influence of the thickness of the self-assembled monolayer, via the alkyl chain length in n-alkyl phosphonic acid-based monolayers on SiO2, on the electronic properties of pentacene-based organic thin-film transistors. Rather than a monotonic increase or decrease in performance with increasing chain length, we have found that the optimum performance occurs with chains of 8-10 carbon atoms. Atomic force microscopy shows a correlation between pentacene crystalline grain size and transistor performance.
AB - Self-assembled monolayers are widely used to modify the gate dielectric/semiconductor interface in organic thin-film transistors. By modifying the interaction between the molecular semiconductor and the substrate, thin-film ordering and the electronic properties of the semiconducting channel can be controlled. The modified semiconductor/dielectric properties result in macroscopically observed changes in the charge-carrier mobilities, threshold voltages, subthreshold swing and transfer characteristic hysteresis. The latter two are determined by the density of charge-trapping states at the interface. Here, we investigate the influence of the thickness of the self-assembled monolayer, via the alkyl chain length in n-alkyl phosphonic acid-based monolayers on SiO2, on the electronic properties of pentacene-based organic thin-film transistors. Rather than a monotonic increase or decrease in performance with increasing chain length, we have found that the optimum performance occurs with chains of 8-10 carbon atoms. Atomic force microscopy shows a correlation between pentacene crystalline grain size and transistor performance.
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U2 - 10.1007/s00339-008-4992-2
DO - 10.1007/s00339-008-4992-2
M3 - Article
AN - SCOPUS:60749114432
SN - 0947-8396
VL - 95
SP - 81
EP - 87
JO - Applied Physics A: Materials Science and Processing
JF - Applied Physics A: Materials Science and Processing
IS - 1
ER -