Improvement of On/Off Ratio in Organic Field-effect Transistor Having Thin Molybdenum Trioxide Layer

Masahiro MINAGAWA; Hidetsugu TAMURA; Ryo SAKIKAWA; Itsuki IKARASHI; Akira BABA; Kazunari SHINBO; Keizo KATO; Futao KANEKO

doi:10.1587/transele.E98.C.98

Improvement of On/Off Ratio in Organic Field-effect Transistor Having Thin Molybdenum Trioxide Layer

Masahiro MINAGAWA, Hidetsugu TAMURA, Ryo SAKIKAWA, Itsuki IKARASHI, Akira BABA, Kazunari SHINBO, Keizo KATO, Futao KANEKO

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We fabricated organic field-effect transistors (OFETs) having a thin layer of molybdenum trioxide (MoO₃), a Lewis acid, and evaluated their electrical characteristics. The insertion of a thin MoO₃ layer reduces the on/off ratio but improves the apparent mobility of the charge carriers. To identify the dominant mechanism responsible for this effect, we characterized devices having a 69-nm-thick pentacene layer with a 1-nm-thick MoO₃ layer either between the gold source and the drain electrodes or only directly under these electrodes. The former device exhibited a low on/off ratio, whereas the latter device exhibited an on/off ratio comparable to those of conventional pentacene OFETs without a thin MoO₃ layer, suggesting that the formation of charge-transfer (CT) complexes immediately above the conduction channel is the critical mechanism. CT complexes at the pentacene/MoO₃ interface immediately above the conduction channel contribute to the formation of an effective channel for off-currents as well as drain currents. Moreover, we also attempted to improve the on/off ratio by using a cloth to rub the surface of a thin MoO₃ layer immediately above the conduction channel to create what we believe to be a profile with abrupt changes in height in the direction of the drain current conduction in OFETs. Consequently, it was found that such a rubbed MoO₃ layer had a surface with a scratched pattern, and the on/off ratio of the OFET was improved, indicating that controlling the CT complex formation by patterning a MoO₃ layer can reduce the off-current in OFETs having a pentacene/MoO₃ active layer.

Publication: IEICE TRANSACTIONS on Electronics Vol.E98-C No.2 pp.98-103

Publication Date: 2015/02/01

Publicized

Online ISSN: 1745-1353

DOI: 10.1587/transele.E98.C.98

Type of Manuscript: Special Section PAPER (Special Section on Recent Progress in Organic Molecular Electronics)

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Authors

Masahiro MINAGAWA
  Nagaoka National College of Technology
Hidetsugu TAMURA
  Nagaoka National College of Technology, Niigata University
Ryo SAKIKAWA
  Nagaoka National College of Technology
Itsuki IKARASHI
  Nagaoka National College of Technology
Akira BABA
  Nagaoka National College of Technology
Kazunari SHINBO
  Niigata University
Keizo KATO
  Niigata University
Futao KANEKO
  Niigata University

Keyword

OFETs, rubbed MoO₃ thin layer, CT complex, Lewis acid

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Masahiro MINAGAWA, Hidetsugu TAMURA, Ryo SAKIKAWA, Itsuki IKARASHI, Akira BABA, Kazunari SHINBO, Keizo KATO, Futao KANEKO, "Improvement of On/Off Ratio in Organic Field-effect Transistor Having Thin Molybdenum Trioxide Layer" in IEICE TRANSACTIONS on Electronics, vol. E98-C, no. 2, pp. 98-103, February 2015, doi: 10.1587/transele.E98.C.98.
Abstract: We fabricated organic field-effect transistors (OFETs) having a thin layer of molybdenum trioxide (MoO₃), a Lewis acid, and evaluated their electrical characteristics. The insertion of a thin MoO₃ layer reduces the on/off ratio but improves the apparent mobility of the charge carriers. To identify the dominant mechanism responsible for this effect, we characterized devices having a 69-nm-thick pentacene layer with a 1-nm-thick MoO₃ layer either between the gold source and the drain electrodes or only directly under these electrodes. The former device exhibited a low on/off ratio, whereas the latter device exhibited an on/off ratio comparable to those of conventional pentacene OFETs without a thin MoO₃ layer, suggesting that the formation of charge-transfer (CT) complexes immediately above the conduction channel is the critical mechanism. CT complexes at the pentacene/MoO₃ interface immediately above the conduction channel contribute to the formation of an effective channel for off-currents as well as drain currents. Moreover, we also attempted to improve the on/off ratio by using a cloth to rub the surface of a thin MoO₃ layer immediately above the conduction channel to create what we believe to be a profile with abrupt changes in height in the direction of the drain current conduction in OFETs. Consequently, it was found that such a rubbed MoO₃ layer had a surface with a scratched pattern, and the on/off ratio of the OFET was improved, indicating that controlling the CT complex formation by patterning a MoO₃ layer can reduce the off-current in OFETs having a pentacene/MoO₃ active layer.
URL: https://globals.ieice.org/en_transactions/electronics/10.1587/transele.E98.C.98/_p

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@ARTICLE{e98-c_2_98,
author={Masahiro MINAGAWA, Hidetsugu TAMURA, Ryo SAKIKAWA, Itsuki IKARASHI, Akira BABA, Kazunari SHINBO, Keizo KATO, Futao KANEKO, },
journal={IEICE TRANSACTIONS on Electronics},
title={Improvement of On/Off Ratio in Organic Field-effect Transistor Having Thin Molybdenum Trioxide Layer},
year={2015},
volume={E98-C},
number={2},
pages={98-103},
abstract={We fabricated organic field-effect transistors (OFETs) having a thin layer of molybdenum trioxide (MoO₃), a Lewis acid, and evaluated their electrical characteristics. The insertion of a thin MoO₃ layer reduces the on/off ratio but improves the apparent mobility of the charge carriers. To identify the dominant mechanism responsible for this effect, we characterized devices having a 69-nm-thick pentacene layer with a 1-nm-thick MoO₃ layer either between the gold source and the drain electrodes or only directly under these electrodes. The former device exhibited a low on/off ratio, whereas the latter device exhibited an on/off ratio comparable to those of conventional pentacene OFETs without a thin MoO₃ layer, suggesting that the formation of charge-transfer (CT) complexes immediately above the conduction channel is the critical mechanism. CT complexes at the pentacene/MoO₃ interface immediately above the conduction channel contribute to the formation of an effective channel for off-currents as well as drain currents. Moreover, we also attempted to improve the on/off ratio by using a cloth to rub the surface of a thin MoO₃ layer immediately above the conduction channel to create what we believe to be a profile with abrupt changes in height in the direction of the drain current conduction in OFETs. Consequently, it was found that such a rubbed MoO₃ layer had a surface with a scratched pattern, and the on/off ratio of the OFET was improved, indicating that controlling the CT complex formation by patterning a MoO₃ layer can reduce the off-current in OFETs having a pentacene/MoO₃ active layer.},
keywords={},
doi={10.1587/transele.E98.C.98},
ISSN={1745-1353},
month={February},}

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TY - JOUR
TI - Improvement of On/Off Ratio in Organic Field-effect Transistor Having Thin Molybdenum Trioxide Layer
T2 - IEICE TRANSACTIONS on Electronics
SP - 98
EP - 103
AU - Masahiro MINAGAWA
AU - Hidetsugu TAMURA
AU - Ryo SAKIKAWA
AU - Itsuki IKARASHI
AU - Akira BABA
AU - Kazunari SHINBO
AU - Keizo KATO
AU - Futao KANEKO
PY - 2015
DO - 10.1587/transele.E98.C.98
JO - IEICE TRANSACTIONS on Electronics
SN - 1745-1353
VL - E98-C
IS - 2
JA - IEICE TRANSACTIONS on Electronics
Y1 - February 2015
AB - We fabricated organic field-effect transistors (OFETs) having a thin layer of molybdenum trioxide (MoO₃), a Lewis acid, and evaluated their electrical characteristics. The insertion of a thin MoO₃ layer reduces the on/off ratio but improves the apparent mobility of the charge carriers. To identify the dominant mechanism responsible for this effect, we characterized devices having a 69-nm-thick pentacene layer with a 1-nm-thick MoO₃ layer either between the gold source and the drain electrodes or only directly under these electrodes. The former device exhibited a low on/off ratio, whereas the latter device exhibited an on/off ratio comparable to those of conventional pentacene OFETs without a thin MoO₃ layer, suggesting that the formation of charge-transfer (CT) complexes immediately above the conduction channel is the critical mechanism. CT complexes at the pentacene/MoO₃ interface immediately above the conduction channel contribute to the formation of an effective channel for off-currents as well as drain currents. Moreover, we also attempted to improve the on/off ratio by using a cloth to rub the surface of a thin MoO₃ layer immediately above the conduction channel to create what we believe to be a profile with abrupt changes in height in the direction of the drain current conduction in OFETs. Consequently, it was found that such a rubbed MoO₃ layer had a surface with a scratched pattern, and the on/off ratio of the OFET was improved, indicating that controlling the CT complex formation by patterning a MoO₃ layer can reduce the off-current in OFETs having a pentacene/MoO₃ active layer.
ER -