Abstract
The authors report the use of high-performance liquid chromatography (HPLC) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) utilizing a gas cluster ion beam to accurately measure the dopant concentration and its depth profile in organic thin films used for organic light-emitting diodes. The total dopant concentrations estimated by HPLC for films of 4,4'-bis(carbazol-9-yl)biphenyl (CBP) doped with tris(2-phenylpyridinato)iridium(III) (Ir(ppy)3) are consistent with those measured by quartz crystal microbalances (QCMs) during the deposition. Concentrations measured for Ir(ppy)3:CBP films by HPLC and TOF-SIMS show a nearly linear relationship in the range of 1-8 wt. %. At concentrations higher than 8 wt. %, TOF-SIMS values significantly deviate because of the matrix effect. The depth profile of the dopant concentration measured by TOF-SIMS was in good agreement with that measured by QCMs during film deposition for concentrations below 8 wt. %. These methods are especially useful for comparing the dopant concentration of films deposited in different batches and equipment.
| Original language | English |
|---|---|
| Article number | 030604 |
| Journal | Journal of Vacuum Science and Technology B:Nanotechnology and Microelectronics |
| Volume | 32 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - May 1 2014 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Instrumentation
- Process Chemistry and Technology
- Surfaces, Coatings and Films
- Materials Chemistry
- Electrical and Electronic Engineering
Cite this
Accurate measurement of dopant concentration in organic light-emitting diodes by combining high-performance liquid chromatography and TOF-SIMS. / Fujimoto, Hiroshi; Edura, Tomohiko; Miyayama, Takuya; Sanada, Noriaki; Adachi, Chihaya.
In: Journal of Vacuum Science and Technology B:Nanotechnology and Microelectronics, Vol. 32, No. 3, 030604, 01.05.2014.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Accurate measurement of dopant concentration in organic light-emitting diodes by combining high-performance liquid chromatography and TOF-SIMS
AU - Fujimoto, Hiroshi
AU - Edura, Tomohiko
AU - Miyayama, Takuya
AU - Sanada, Noriaki
AU - Adachi, Chihaya
PY - 2014/5/1
Y1 - 2014/5/1
N2 - The authors report the use of high-performance liquid chromatography (HPLC) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) utilizing a gas cluster ion beam to accurately measure the dopant concentration and its depth profile in organic thin films used for organic light-emitting diodes. The total dopant concentrations estimated by HPLC for films of 4,4'-bis(carbazol-9-yl)biphenyl (CBP) doped with tris(2-phenylpyridinato)iridium(III) (Ir(ppy)3) are consistent with those measured by quartz crystal microbalances (QCMs) during the deposition. Concentrations measured for Ir(ppy)3:CBP films by HPLC and TOF-SIMS show a nearly linear relationship in the range of 1-8 wt. %. At concentrations higher than 8 wt. %, TOF-SIMS values significantly deviate because of the matrix effect. The depth profile of the dopant concentration measured by TOF-SIMS was in good agreement with that measured by QCMs during film deposition for concentrations below 8 wt. %. These methods are especially useful for comparing the dopant concentration of films deposited in different batches and equipment.
AB - The authors report the use of high-performance liquid chromatography (HPLC) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) utilizing a gas cluster ion beam to accurately measure the dopant concentration and its depth profile in organic thin films used for organic light-emitting diodes. The total dopant concentrations estimated by HPLC for films of 4,4'-bis(carbazol-9-yl)biphenyl (CBP) doped with tris(2-phenylpyridinato)iridium(III) (Ir(ppy)3) are consistent with those measured by quartz crystal microbalances (QCMs) during the deposition. Concentrations measured for Ir(ppy)3:CBP films by HPLC and TOF-SIMS show a nearly linear relationship in the range of 1-8 wt. %. At concentrations higher than 8 wt. %, TOF-SIMS values significantly deviate because of the matrix effect. The depth profile of the dopant concentration measured by TOF-SIMS was in good agreement with that measured by QCMs during film deposition for concentrations below 8 wt. %. These methods are especially useful for comparing the dopant concentration of films deposited in different batches and equipment.
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UR - http://www.scopus.com/inward/citedby.url?scp=85008259835&partnerID=8YFLogxK
U2 - 10.1116/1.4871756
DO - 10.1116/1.4871756
M3 - Article
VL - 32
JO - Journal of Vacuum Science and Technology B:Nanotechnology and Microelectronics
JF - Journal of Vacuum Science and Technology B:Nanotechnology and Microelectronics
SN - 2166-2746
IS - 3
M1 - 030604
ER -