Accession Number : ADA259043


Title :   Processability of Polythiophene Thin Films by Ultraviolet Photo Bleaching


Descriptive Note : Master's thesis


Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING


Personal Author(s) : Fletcher, Derek D


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a259043.pdf


Report Date : Dec 1992


Pagination or Media Count : 53


Abstract : Materials possessing strong chi(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 (0-)5 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/sqcm), 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 chi(3) property is affected after the 60 minute UV exposure.... Polythiophene, Photo bleaching, Nonlinear optics, Optical switching.


Descriptors :   *POLYMERS , *THIN FILMS , *OPTICAL SWITCHING , EXTINCTION , OPTICAL PROPERTIES , OPTICS , REFRACTIVE INDEX , THESES , NONLINEAR OPTICS , TIME , ROUGHNESS , ULTRAVIOLET EQUIPMENT , SWITCHING , INDEXES , DROPS , COEFFICIENTS , INTERNAL , BOUNDARIES , SURFACES , INTERNAL REFLECTION , SWITCHES , REFLECTION , VAPOR DEPOSITION , FILMS , RADIATION , THICKNESS , PRODUCTION , MATERIALS


Subject Categories : Physical Chemistry
      Polymer Chemistry
      Optics


Distribution Statement : APPROVED FOR PUBLIC RELEASE