Hostname: page-component-77c89778f8-rkxrd Total loading time: 0 Render date: 2024-07-17T15:35:22.556Z Has data issue: false hasContentIssue false

p-Type Doping of Small-Molecule Organic Semiconductors using Organic Vapor Phase Deposition (OVPD)

Published online by Cambridge University Press:  14 February 2012

M. Brast
Affiliation:
Device Technology, RWTH Aachen University, Sommerfeldstr. 24, 52074 Aachen, Germany
F. Lindla
Affiliation:
Device Technology, RWTH Aachen University, Sommerfeldstr. 24, 52074 Aachen, Germany
M. Boesing
Affiliation:
Device Technology, RWTH Aachen University, Sommerfeldstr. 24, 52074 Aachen, Germany
D. Bertram
Affiliation:
Philips Technologie GmbH, Philipsstraße 8, 52068 Aachen, Germany
D. Keiper
Affiliation:
AIXTRON SE, Kaiserstraße 98, 52134 Herzogenrath, Germany
M. Heuken
Affiliation:
Device Technology, RWTH Aachen University, Sommerfeldstr. 24, 52074 Aachen, Germany AIXTRON SE, Kaiserstraße 98, 52134 Herzogenrath, Germany
H. Kalisch
Affiliation:
Device Technology, RWTH Aachen University, Sommerfeldstr. 24, 52074 Aachen, Germany
A. Vescan
Affiliation:
Device Technology, RWTH Aachen University, Sommerfeldstr. 24, 52074 Aachen, Germany
Get access

Abstract

In the past few years, organic vapor phase deposition (OVPD) has been demonstrated to be an effective deposition method for high-performance monochrome and white organic light emitting diodes (OLEDs) [1-4]. OVPD provides good material utilization efficiency and large achievable deposition rates.

An application of p-type doping is the improvement of hole injection either from the anode contact or from a charge generation layer in stacked OLEDs [5]. Nevertheless, no reports on p-type doping using OVPD can be found in literature, in part due to the thermal instability and high chemical sensitivity of organic dopants.

In this work, p-type doping using an AIXTRON Gen-1 OVPD tool with two different show-erhead designs is examined. NDP-2 (NOVALED) and N,N‘-diphenyl-N,N‘-bis(1-naphthylphenyl)-1,1‘-biphenyl-4,4‘-diamine (NPB) were used as p-type dopant (guest) and hole-conducting host, respectively. p-Type doped hole-only devices were fabricated and compared with undoped ones.

Two different showerhead designs (made either of aluminum or stainless steel) were investi-gated with respect to OLED performance to determine possible side reactions.

Highly efficient monochrome red OLEDs including a p-type doped hole transport layer were demonstrated exhibiting a current efficiency of 31 cd/A, a power efficiency of 26 lm/W and a driving voltage of 3.7 V without improved light outcoupling (all values at 1000 cd/m2).

Type
Research Article
Copyright
Copyright © Materials Research Society 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Lindla, F., Boesing, M., et al. ., Appl. Phys. Lett. 95 (21), 213305 (2009).Google Scholar
2. Lindla, F., Boesing, M., et al. ., J. Photon. Energy. 1 (1), 011013 (2011).Google Scholar
3. Zhou, T. X., Ngo, T., et al. ., Appl. Phys. Lett. 86 (2), 021107 (2005).Google Scholar
4. Lunt, R. R., Benziger, J. B., et al. ., Appl. Phys. Lett. 90 (18), 181932 (2007).Google Scholar
5. Kanno, H., Giebink, N. C., et al. ., Appl. Phys. Lett. 89 (2), 023503 (2006).Google Scholar
6. Tang, C. W. and VanSlyke, S. A., Appl. Phys. Lett. 51, 913915 (1987).Google Scholar
7. Stössel, M., Staudigel, J., et al. ., Appl. Phys. A 68 (4), 387-390 (1999).Google Scholar
8. Wang, F., Qiao, X., et al. ., Organic Electronics 9 (6), 985-993 (2008).Google Scholar
9. Wang, F., Qiao, X., et al. ., J. Appl. Phys 105 (8), 084518 (2009).Google Scholar
10. Chan, C. K., Amy, F., et al. ., Chemical Physics Letters 431 (1–3), 67-71 (2006).Google Scholar
11. Law, C. W., Lau, K. M., et al. ., Appl. Phys. Lett. 89 (13), 133511 (2006).Google Scholar
12. Blochwitz, J., Pfeiffer, M., et al. ., Appl. Phys. Lett. 73 (6), 729-731 (1998).Google Scholar
13. Ganzorig, C. and Fujihira, M., Appl. Phys. Lett. 77 (25), 4211-4213 (2000).Google Scholar
14. Romero, D. B., Schaer, M., et al. ., Appl. Phys. Lett. 67 (12), 1659-1661 (1995).Google Scholar
15. Schwambera, M., in Proc. of ASID (2006).Google Scholar
16. Meyer, N., Rusu, M., et al. ., Eur. Phys. J. Appl. Phys. 46 (12506) (2009).Google Scholar
17. van Gemmern, P., Dissertation, RWTH-Aachen University, 2008.Google Scholar
18. Lindla, F., Boesing, M., et al. ., MRS Symposium Proceedings. 1154 (2009).Google Scholar