Hostname: page-component-8448b6f56d-cfpbc Total loading time: 0 Render date: 2024-04-16T21:19:57.620Z Has data issue: false hasContentIssue false

UV Resistant Poly(3,4-ethylenedioxythiophene) Thin Films: Layer-by-Layer Assembly with Absorbing Nanoparticles

Published online by Cambridge University Press:  01 February 2011

Thomas Dawidczyk
Affiliation:
Texas A&M University, Mechanical Engineering, Texas A&M University, College Station, TX, 77843, United States
Jaime Grunlan
Affiliation:
jgrunlan@tamu.edu, Texas A&M University, Materials Science and Engineering, 3003 TAMU, College Station, TX, 77843, United States
Get access

Abstract

Layer-by-layer (LbL) assembly is used to create thin films by alternately exposing a substrate to positively- and negatively-charged molecules or particles in water. In recent years, LbL assemblies containing poly(3,4-ethylenedioxythiophene) (PEDOT) have been heavily studied, but little work has focused on improving the environmental stability of these thin films. Most intrinsically conductive polymers suffer from increasing resistance with exposure to ultraviolet light. In the present work, photolytic stability is improved by adding UV-absorbing nanoparticles to PEDOT assemblies. Films made by alternately depositing PEDOT-PSS and polyethylenimine (PEI) show an order of magnitude increase in sheet resistance after just 28 hours of exposure to 365 nm light. This degradation is cut in half by incorporating UV-absorbing nanoparticles, carbon black or titanium dioxide, into these assemblies. After more than 200 hours of exposure, films containing TiO2 nanoparticles have sheet resistance that is one fifth that of the unprotected PEDOT. In addition to adding UV-absorbing particles, the influence of doping and type of polycation on bulk resistivity and film growth were evaluated. These films are able to achieve bulk resistivity values below 1 Ohm cm with a thickness below 100 nm. When combined with transparency greater than 90%, these films may be useful for electrostatic dissipation layers or low conductivity electrodes in film or flexible display applications.

Type
Research Article
Copyright
Copyright © Materials Research Society 2008

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. Decher, G. and Schlenoff, J. B. in Multilayer Thin Films – Sequential Assembly of Nanocomposite Materials, (Wiley-VCH: Weinheim, Germany, 2003).Google Scholar
2. Grunlan, J. C., Choi, J. K. and Lin, A., Biomacromolecules 6, 1149 (2005).Google Scholar
3. Hiller, J., Mendelsohn, J. D., and Rubner, M. F., Nature Materials 1, 59 (2002).Google Scholar
4. DeLongchamp, D. M., Kastantin, M., and Hammond, P. T., Chem. Mater. 15, 1575 (2003).Google Scholar
5. Jang, W. S., Rawson, I. and Grunlan, J. C., Thin Solid Films (2008) in press (available online).Google Scholar
6. Yu, H. H., Cao, T., Zhou, L. D., Gu, E. D., Yu, D. S. and Jiang, D. S., Sens. Actuat. B 119, 512 (2006).Google Scholar
7. Smith, R. R., Smith, A. P., Stricker, J. T., Taylor, B. E. and Durstock, M. F., Macromolecules 39, 6071 (2006).Google Scholar
8. Tang, Z., Donohoe, S. T., Robinson, J. M., Chiarelli, P. A. and Wang, H. L., Polymer 46, 9043 (2005).Google Scholar
9. Heywang, G. and Jonas, F., Advanced Materials 4, 116 (1992).Google Scholar
10. Jan, C. J., Walton, M. D., McConnell, E. P., Jang, W. S., Kim, Y. S. and Grunlan, J. C., Carbon 44, 1974 (2006).Google Scholar
11. Schoeler, B., Poptoshev, E., and Caruso, F., Macromolecules 36, 5258 (2003).Google Scholar
12. Tang, Z. X., Donohoe, S. T., Robinson, J. A., Chiarelli, P. A. and Wang, H. L., Polymer 46, 9043 (2005).Google Scholar