A flexible amorphous Bi(5)Nb(3)O(15) film for the gate insulator of the low-voltage operating pentacene thin-film transistor fabricated at room temperature.
The amorphous Bi(5)Nb(3)O(15) film grown at room temperature under an oxygen-plasma sputtering ambient (BNRT-O(2) film) has a hydrophobic surface with a surface energy of 35.6 mJ m(-2), which is close to that of the orthorhombic pentacene (38 mJ m(-2)), resulting in the formation of a good pentacene layer without the introduction of an additional polymer layer. This film was very flexible, maintaining a high capacitance of 145 nF cm(-2) during and after 10(5) bending cycles with a small curvature radius of 7.5 mm. This film was optically transparent. Furthermore, the flexible, pentacene-based, organic thin-film transistors (OTFTs) fabricated on the poly(ether sulfone) substrate at room temperature using a BNRT-O(2) film as a gate insulator exhibited a promising device performance with a high field effect mobility of 0.5 cm(2) V(-1) s(-1), an on/off current modulation of 10(5), and a small subthreshold slope of 0.2 V decade(-1) under a low operating voltage of -5 V. This device also maintained a high carrier mobility of 0.45 cm(2) V(-1 )s(-1) during the bending with a small curvature radius of 9 mm. Therefore, the BNRT-O(2) film is considered a promising material for the gate insulator of the flexible, pentacene-based OTFT.
Cho
Kyung-Hoon
KH
Department of Materials Science and Engineering, Korea University, 1-5 Ga, Anam-Dong, Seongbuk-Gu, Seoul 136-713, Korea.
Seong
Tae-Geun
TG
Choi
Joo-Young
JY
Kim
Jin-Seong
JS
Kwon
Jae-Hong
JH
Shin
Sang-Il
SI
Chung
Myung-Ho
MH
Ju
Byeong-Kwon
BK
Nahm
Sahn
S