TY - JOUR
T1 - ITO-free organic light-emitting diodes with MoO 3 /Al/MoO 3 as semitransparent anode fabricated using thermal deposition method
AU - Lu, Hsin Wei
AU - Huang, Ching Wen
AU - Kao, Po Ching
AU - Chu, Sheng Yuan
N1 - Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2015
Y1 - 2015
N2 - Abstract In this paper, semitransparent electrodes with the structure substrate/MoO 3 /Al/MoO 3 (OMO) were fabricated via the thermal deposition method for use as the anode in organic light-emitting diodes (OLEDs). The optical transmittance of the metal layer was enhanced by depositing metal oxidation (MoO 3 ) and metal (Al) layers. The optimal thickness of the Al thin films was determined to be 15 nm for high optical transmittance and good electrical conductivity. The optimized films show the typical sheet resistance of 7 Ω/sq and a high transmittance of 70% at 550 nm. The indium-tin-oxide (ITO)-free OLEDs with the fabricated composite anodes on a glass substrate exhibited the high luminance and current efficiency of 21,750 cd/m 2 and 3.18 cd/A, respectively. In addition, bending effects on the polyethersulfone (PES) substrate/MoO 3 /Al/MoO 3 and PES substrate/MoO 3 /Al structures were investigated. Cracks formed on the surface of the samples with a bending radius smaller than or equal to 1 cm. MoO 3 covering the Al layer modifies the surface of the electrode and enhances durability. The surface roughness of the bi-layer films was higher than that of the tri-layer films. Therefore, OLEDs with OMO anode outperform those with bi-layer films anode.
AB - Abstract In this paper, semitransparent electrodes with the structure substrate/MoO 3 /Al/MoO 3 (OMO) were fabricated via the thermal deposition method for use as the anode in organic light-emitting diodes (OLEDs). The optical transmittance of the metal layer was enhanced by depositing metal oxidation (MoO 3 ) and metal (Al) layers. The optimal thickness of the Al thin films was determined to be 15 nm for high optical transmittance and good electrical conductivity. The optimized films show the typical sheet resistance of 7 Ω/sq and a high transmittance of 70% at 550 nm. The indium-tin-oxide (ITO)-free OLEDs with the fabricated composite anodes on a glass substrate exhibited the high luminance and current efficiency of 21,750 cd/m 2 and 3.18 cd/A, respectively. In addition, bending effects on the polyethersulfone (PES) substrate/MoO 3 /Al/MoO 3 and PES substrate/MoO 3 /Al structures were investigated. Cracks formed on the surface of the samples with a bending radius smaller than or equal to 1 cm. MoO 3 covering the Al layer modifies the surface of the electrode and enhances durability. The surface roughness of the bi-layer films was higher than that of the tri-layer films. Therefore, OLEDs with OMO anode outperform those with bi-layer films anode.
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U2 - 10.1016/j.apsusc.2015.03.188
DO - 10.1016/j.apsusc.2015.03.188
M3 - Article
AN - SCOPUS:84931301200
SN - 0169-4332
VL - 347
SP - 116
EP - 121
JO - Applied Surface Science
JF - Applied Surface Science
M1 - 30065
ER -