Photo-Induced Threshold and Onset Voltage Shifts in Organic Thin-Film Transistors

Ichiro FUJIEDA; Tse Nga NG; Tomoya HOSHINO; Tomonori HANASAKI

doi:10.1587/transele.E96.C.1360

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Photo-Induced Threshold and Onset Voltage Shifts in Organic Thin-Film Transistors

Ichiro FUJIEDA, Tse Nga NG, Tomoya HOSHINO, Tomonori HANASAKI

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We have studied photo-induced effects in a p-type transistor based on a [1]benzothieno[3,2-b]benzothiophene (BTBT) derivative. Repetition of blue light irradiation and electrical characterization under dark reveals that its threshold voltage gradually shifts in the positive direction as the cumulative exposure time increases. This shift is slowly reversed when the transistor is stored under dark. The onset voltage defined as the gate bias at which the sub-threshold current exceeds a certain level behaves in a similar manner. Mobility remains more or less the same during this exposure period and the storage period. Time evolution of the threshold voltage shift is fit by a model assuming two charged meta-stable states decaying independently. A set of parameters consists of a decay constant for each state and the ratio of the two states. A single parameter set reproduces the positive shift during the exposure period and the negative shift during the storage period. Time evolution of the onset voltage is reproduced by the same parameter set. We have also studied photo-induced effects in two types of n-type transistors where either a pure solution of a perylene derivative or a solution mixed with an insulating polymer is used for printing each semiconductor layer. A similar behavior is observed for these transistors: blue light irradiation under a negative gate bias shifts the threshold and the onset voltages in the negative direction and these shifts are reversed under dark. The two-component model reproduces the behavior of these voltage shifts and the parameter set is slightly different among the two transistors made from different semiconductor solutions. The onset voltage shift is well correlated to the threshold voltage shift for the three types of organic transistors studied here. The onset voltage is more sensitive to illumination than the threshold voltage and its sensitivity differs among transistors.

Publication: IEICE TRANSACTIONS on Electronics Vol.E96-C No.11 pp.1360-1366

Publication Date: 2013/11/01

Publicized

Online ISSN: 1745-1353

DOI: 10.1587/transele.E96.C.1360

Type of Manuscript: Special Section INVITED PAPER (Special Section on Electronic Displays)

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Authors

Ichiro FUJIEDA
  Ritsumeikan University
Tse Nga NG
  Palo Alto Research Center
Tomoya HOSHINO
  Ritsumeikan University
Tomonori HANASAKI
  Ritsumeikan University

Keyword

organic transistor, persistent photoconductivity, threshold voltage, onset voltage

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Ichiro FUJIEDA, Tse Nga NG, Tomoya HOSHINO, Tomonori HANASAKI, "Photo-Induced Threshold and Onset Voltage Shifts in Organic Thin-Film Transistors" in IEICE TRANSACTIONS on Electronics, vol. E96-C, no. 11, pp. 1360-1366, November 2013, doi: 10.1587/transele.E96.C.1360.
Abstract: We have studied photo-induced effects in a p-type transistor based on a [1]benzothieno[3,2-b]benzothiophene (BTBT) derivative. Repetition of blue light irradiation and electrical characterization under dark reveals that its threshold voltage gradually shifts in the positive direction as the cumulative exposure time increases. This shift is slowly reversed when the transistor is stored under dark. The onset voltage defined as the gate bias at which the sub-threshold current exceeds a certain level behaves in a similar manner. Mobility remains more or less the same during this exposure period and the storage period. Time evolution of the threshold voltage shift is fit by a model assuming two charged meta-stable states decaying independently. A set of parameters consists of a decay constant for each state and the ratio of the two states. A single parameter set reproduces the positive shift during the exposure period and the negative shift during the storage period. Time evolution of the onset voltage is reproduced by the same parameter set. We have also studied photo-induced effects in two types of n-type transistors where either a pure solution of a perylene derivative or a solution mixed with an insulating polymer is used for printing each semiconductor layer. A similar behavior is observed for these transistors: blue light irradiation under a negative gate bias shifts the threshold and the onset voltages in the negative direction and these shifts are reversed under dark. The two-component model reproduces the behavior of these voltage shifts and the parameter set is slightly different among the two transistors made from different semiconductor solutions. The onset voltage shift is well correlated to the threshold voltage shift for the three types of organic transistors studied here. The onset voltage is more sensitive to illumination than the threshold voltage and its sensitivity differs among transistors.
URL: https://global.ieice.org/en_transactions/electronics/10.1587/transele.E96.C.1360/_p

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@ARTICLE{e96-c_11_1360,
author={Ichiro FUJIEDA, Tse Nga NG, Tomoya HOSHINO, Tomonori HANASAKI, },
journal={IEICE TRANSACTIONS on Electronics},
title={Photo-Induced Threshold and Onset Voltage Shifts in Organic Thin-Film Transistors},
year={2013},
volume={E96-C},
number={11},
pages={1360-1366},
abstract={We have studied photo-induced effects in a p-type transistor based on a [1]benzothieno[3,2-b]benzothiophene (BTBT) derivative. Repetition of blue light irradiation and electrical characterization under dark reveals that its threshold voltage gradually shifts in the positive direction as the cumulative exposure time increases. This shift is slowly reversed when the transistor is stored under dark. The onset voltage defined as the gate bias at which the sub-threshold current exceeds a certain level behaves in a similar manner. Mobility remains more or less the same during this exposure period and the storage period. Time evolution of the threshold voltage shift is fit by a model assuming two charged meta-stable states decaying independently. A set of parameters consists of a decay constant for each state and the ratio of the two states. A single parameter set reproduces the positive shift during the exposure period and the negative shift during the storage period. Time evolution of the onset voltage is reproduced by the same parameter set. We have also studied photo-induced effects in two types of n-type transistors where either a pure solution of a perylene derivative or a solution mixed with an insulating polymer is used for printing each semiconductor layer. A similar behavior is observed for these transistors: blue light irradiation under a negative gate bias shifts the threshold and the onset voltages in the negative direction and these shifts are reversed under dark. The two-component model reproduces the behavior of these voltage shifts and the parameter set is slightly different among the two transistors made from different semiconductor solutions. The onset voltage shift is well correlated to the threshold voltage shift for the three types of organic transistors studied here. The onset voltage is more sensitive to illumination than the threshold voltage and its sensitivity differs among transistors.},
keywords={},
doi={10.1587/transele.E96.C.1360},
ISSN={1745-1353},
month={November},}

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TY - JOUR
TI - Photo-Induced Threshold and Onset Voltage Shifts in Organic Thin-Film Transistors
T2 - IEICE TRANSACTIONS on Electronics
SP - 1360
EP - 1366
AU - Ichiro FUJIEDA
AU - Tse Nga NG
AU - Tomoya HOSHINO
AU - Tomonori HANASAKI
PY - 2013
DO - 10.1587/transele.E96.C.1360
JO - IEICE TRANSACTIONS on Electronics
SN - 1745-1353
VL - E96-C
IS - 11
JA - IEICE TRANSACTIONS on Electronics
Y1 - November 2013
AB - We have studied photo-induced effects in a p-type transistor based on a [1]benzothieno[3,2-b]benzothiophene (BTBT) derivative. Repetition of blue light irradiation and electrical characterization under dark reveals that its threshold voltage gradually shifts in the positive direction as the cumulative exposure time increases. This shift is slowly reversed when the transistor is stored under dark. The onset voltage defined as the gate bias at which the sub-threshold current exceeds a certain level behaves in a similar manner. Mobility remains more or less the same during this exposure period and the storage period. Time evolution of the threshold voltage shift is fit by a model assuming two charged meta-stable states decaying independently. A set of parameters consists of a decay constant for each state and the ratio of the two states. A single parameter set reproduces the positive shift during the exposure period and the negative shift during the storage period. Time evolution of the onset voltage is reproduced by the same parameter set. We have also studied photo-induced effects in two types of n-type transistors where either a pure solution of a perylene derivative or a solution mixed with an insulating polymer is used for printing each semiconductor layer. A similar behavior is observed for these transistors: blue light irradiation under a negative gate bias shifts the threshold and the onset voltages in the negative direction and these shifts are reversed under dark. The two-component model reproduces the behavior of these voltage shifts and the parameter set is slightly different among the two transistors made from different semiconductor solutions. The onset voltage shift is well correlated to the threshold voltage shift for the three types of organic transistors studied here. The onset voltage is more sensitive to illumination than the threshold voltage and its sensitivity differs among transistors.
ER -