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Title: Conformation-Dependent Photostability among and within Single Conjugated Polymers

Journal Article · · Nano Letters
 [1];  [1];  [2];  [1];  [1]
  1. Columbia Univ., New York, NY (United States)
  2. Columbia Univ., New York, NY (United States); Sungkyunkwan Univ., Suwon (Korea)

The relationship between photostability and conformation of 2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene (MEH-PPV) conjugated polymers was studied via excitation polarization modulation depth (M) measurements. Upon partial photobleaching, M distributions of collapsed, highly ordered MEH-PPV molecules shifted toward lower values. Conversely, M distributions of MEH-PPV molecules with random coil conformations moved toward higher values after partial photobleaching. Monte Carlo simulations of randomly distributed dipole moments along polymer chains subjected to partial photobleaching revealed that a statistical effect leads to an increase in peak M value. Decreases in M values seen experimentally in the population of MEH-PPV molecules with high M values, however, are due to conformation-dependent photostability within single MEH-PPV polymers. Here, we show that, while folded MEH-PPV molecules are relatively more photostable than extended MEH-PPV molecules in an ensemble, extended portions of particular molecules are more photostable than folded domains within single MEH-PPV molecules.

Research Organization:
Energy Frontier Research Centers (EFRC) (United States). Re-Defining Photovoltaic Efficiency Through Molecule Scale Control (RPEMSC)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF)
Grant/Contract Number:
SC0001085; CHE 1213242
OSTI ID:
1370363
Journal Information:
Nano Letters, Vol. 15, Issue 11; Related Information: RPEMSC partners with Columbia University (lead); Brookhaven National Laboratory; Purdue University; ISSN 1530-6984
Publisher:
American Chemical SocietyCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 14 works
Citation information provided by
Web of Science

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Cited By (3)

In Situ Optical Imaging of the Growth of Conjugated Polymer Aggregates journal January 2018
Super-resolution Fluorescence Imaging for Materials Science journal August 2017
In Situ Optical Imaging of the Growth of Conjugated Polymer Aggregates journal January 2018