TY - JOUR
T1 - Carrier injection characteristics of metal/tris-(8-hydroxyquinoline) aluminum interface with long chain alkane insertion layer
AU - Abiko, Naofumi
AU - Sugi, Keiji
AU - Suenaga, Tamotsu
AU - Kimura, Yasuo
AU - Ishh, Hisao
AU - Niwano, Michio
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2006/1/20
Y1 - 2006/1/20
N2 - We have examined charge carrier injection from electrodes to tris(8-hydroxyquinoline) aluminum (Alq3) with insulator insertion layers by displacement current measurement (DCM). The inserted materials we used are LiF and a long chain alkane C44H90 (TTC). First, the device structures of Au (or Al)/TTC (or LiF)/Alq3/SiO2/Si were examined by DCM. In the case of the Au/Alq3 interface, we found that the threshold voltage for hole injection from the Au electrode to the Alq3 layer was much reduced by the insertion of a 10-nm-thick TTC layer. In the case of the Al/Alq3 interface, the threshold voltage for electron injection from the Al electrode to the Alq3 layer was reduced by the insertion of a 1-nm-thick TTC layer. The reduction in the threshold voltage was compatible to that in the case of LiF insertion. From these results, we can expect that TTC insertion can reduce the operation voltage of organic light-emitting diodes (OLEDs). However, no improvement in performance was observed in the Al/Alq3/TPD/indium tin oxide (ITO) device, indicating that the reduction in the threshold voltage for carrier injection does not directly correspond to efficient injection in the high current region.
AB - We have examined charge carrier injection from electrodes to tris(8-hydroxyquinoline) aluminum (Alq3) with insulator insertion layers by displacement current measurement (DCM). The inserted materials we used are LiF and a long chain alkane C44H90 (TTC). First, the device structures of Au (or Al)/TTC (or LiF)/Alq3/SiO2/Si were examined by DCM. In the case of the Au/Alq3 interface, we found that the threshold voltage for hole injection from the Au electrode to the Alq3 layer was much reduced by the insertion of a 10-nm-thick TTC layer. In the case of the Al/Alq3 interface, the threshold voltage for electron injection from the Al electrode to the Alq3 layer was reduced by the insertion of a 1-nm-thick TTC layer. The reduction in the threshold voltage was compatible to that in the case of LiF insertion. From these results, we can expect that TTC insertion can reduce the operation voltage of organic light-emitting diodes (OLEDs). However, no improvement in performance was observed in the Al/Alq3/TPD/indium tin oxide (ITO) device, indicating that the reduction in the threshold voltage for carrier injection does not directly correspond to efficient injection in the high current region.
KW - Charge carrier injection
KW - Displacement current measurement (DCM)
KW - Insulator
KW - Interface
KW - Organic light-emitting diode (OLED)
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U2 - 10.1143/JJAP.45.442
DO - 10.1143/JJAP.45.442
M3 - Article
AN - SCOPUS:31844456787
VL - 45
SP - 442
EP - 446
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 1 B
ER -