TY - JOUR
T1 - Solution-processed barium salts as charge injection layers for high performance N-channel organic field-effect transistors
AU - Kim, Nam Koo
AU - Khim, Dongyoon
AU - Xu, Yong
AU - Lee, Seung Hoon
AU - Kang, Minji
AU - Kim, Jihong
AU - Facchetti, Antonio
AU - Noh, Yong Young
AU - Kim, Dong Yu
PY - 2014/6/25
Y1 - 2014/6/25
N2 - N-channel organic field-effect transistors (OFETs) have generally shown lower field-effect mobilities (μFET) than their p-type counterparts. One of the reasons is the energetic misalignment between the work function (WF) of commonly used charge injection electrode, i.e. gold (Au), and the lowest unoccupied molecular orbital (LUMO) of n-channel electron- transporting organic semiconductors. Here, we report barium salts as solution-processed interlayers, to improve the electron-injection and/or hole-blocking in top-gate/bottom-contact n-channel OFETs, based on poly{[N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl] -alt-5,5'-(2,2'-dithiophene)} (P(NDI2OD-T2)) and phenyl-C61-butyric acid methyl ester (PC61BM). Two different barium salts, barium hydroxide (Ba(OH)2) and barium chloride (Ba(Cl)2), are employed as the ultrathin interlayer (∼2 nm); and they effectively tune the WF of Au from 4.9 eV, to as low as 3.5 eV. The resulting n-channel OFETs exhibit significantly improved μFET, approaching 2.6 cm2/(V s) and 0.1 cm2/(V s) for the best P(NDI2OD-T2) and PC61BM devices, respectively, with Ba(OH)2 as interlayer.
AB - N-channel organic field-effect transistors (OFETs) have generally shown lower field-effect mobilities (μFET) than their p-type counterparts. One of the reasons is the energetic misalignment between the work function (WF) of commonly used charge injection electrode, i.e. gold (Au), and the lowest unoccupied molecular orbital (LUMO) of n-channel electron- transporting organic semiconductors. Here, we report barium salts as solution-processed interlayers, to improve the electron-injection and/or hole-blocking in top-gate/bottom-contact n-channel OFETs, based on poly{[N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl] -alt-5,5'-(2,2'-dithiophene)} (P(NDI2OD-T2)) and phenyl-C61-butyric acid methyl ester (PC61BM). Two different barium salts, barium hydroxide (Ba(OH)2) and barium chloride (Ba(Cl)2), are employed as the ultrathin interlayer (∼2 nm); and they effectively tune the WF of Au from 4.9 eV, to as low as 3.5 eV. The resulting n-channel OFETs exhibit significantly improved μFET, approaching 2.6 cm2/(V s) and 0.1 cm2/(V s) for the best P(NDI2OD-T2) and PC61BM devices, respectively, with Ba(OH)2 as interlayer.
KW - barium salts
KW - charge injection
KW - interlayer
KW - organic field-effect transistor
KW - work function
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U2 - 10.1021/am502007j
DO - 10.1021/am502007j
M3 - Article
C2 - 24893277
AN - SCOPUS:84903537068
SN - 1944-8244
VL - 6
SP - 9614
EP - 9621
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 12
ER -