Molecular oxygen and moisture as traps in poly[2-methoxy-5-(2[sup ′]-ethylhexyloxy)-1,4-phenylene vinylene]: locations and detrapping by chain relaxation

Tseng, Hao-En; Peng, Kang-Yung; Chen, Show-An
June 2003
Applied Physics Letters;6/9/2003, Vol. 82 Issue 23, p4086
Academic Journal
We investigate locations of molecular oxygen and moisture (O[SUB2]/H[SUB2]O) serving as traps in poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV) by measurements of field-induced thermally stimulated current, photoexcitation thermally stimulated current (PE-TSC), and dynamic mechanical analysis. Two broad peaks of PE-TSC are found at 212 and 325 K in the samples with O[SUB2]/H[SUB2]O-rich MEH-PPV, which are in reasonable agreement with those of the side chain and main chain relaxation, respectively. These traps can be attributed to the presence of O[SUB2]/H[SUB2]O (most likely molecular oxygen) in the side chain region and the amorphous main chain region, and the detrapping process is induced by chain motions under elevated temperatures.


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