Exciton Migration and Photo-induced Degradation of MEH-PPV Organic Semiconducting Material in Solutions and Thin Films


Cole Galey

Document Type


Degree Name

Master of Science (MS)


Physics and Astronomy

Date of Award

Spring 2019


The study of MEH-PPV, Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], has been of great interest to researchers for its semiconducting properties, leading to the practical applications of creating organic light emitting diodes and solar cell devices. This research is focused on the study of the mechanisms responsible for the photoluminescent degradation of MEH-PPV in both solutions and thin films. When comparing the initial photoluminescent spectrum of MEH-PPV in film and solution, a blue shift is observed during the degradation. The blue shift is the result of strong interchain exciton migration in the thin film. MEH-PPV dissolved in a chloroform solution degraded differently than MEH-PPV deposited on as a thin film. A large blue shift is observed as the thin film degrades, while a small blue shift is observed for the solution. This is compelling evidence for possible photochemical reaction caused by excition migration between thin films and solutions. UV-Vis and FTIR spectroscopy performed on films and solutions produced similar spectra as the films and solutions degraded. Based on the FTIR data, chloroform plays no significant role in the degradation process.


Heungman Park

Subject Categories

Physical Sciences and Mathematics | Physics