Processability of Polythiophene Thin Films by Ultraviolet Photo Bleaching

Author

Derek D. Fletcher

Date of Award

12-1992

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Engineering Physics

First Advisor

Peter Haaland, PhD

Abstract

Materials possessing strong 𝜒⁽³⁾ optical properties such as Polythiophene are sought for the production of optical switches. Polythiophene thin films produced by plasma enhanced CVD show a surface rms roughness of 10^-15 angstroms over single square micron areas which is acceptable for wave guiding in the near IR. This research investigates permanently changing the optical properties of such a thin film by exposure to UV radiation (254 nm, 35 mW/cm²), known as photo bleaching, in hope of creating a refractive index boundary for use in total internal reflection. After 60 minutes exposure the refractive index shows a slight increase of 0.9% at 800 nm. The extinction coefficient shows a change of 218% at 500 nm. There is a corresponding increase in absorbance of 160% at 500 nm, but this increase is seen to drop off at 700 nm. The thin films are observed to lose thickness exponentially over time as a result of out-gasing in the film. It is not known if the 𝜒⁽³⁾ property is affected after the 60 minute UV exposure.

AFIT Designator

AFIT-GEP-ENP-92D-03

DTIC Accession Number

ADA259043

Comments

The author's Vita page is omitted.

Recommended Citation

Fletcher, Derek D., "Processability of Polythiophene Thin Films by Ultraviolet Photo Bleaching" (1992). Theses and Dissertations. 7183.
https://scholar.afit.edu/etd/7183