Electron Trap Dynamics in Polymer Light?Emitting Diodes
نویسندگان
چکیده
Semiconducting polymers are being studied intensively for optoelectronic device applications, including solution-processed light-emitting diodes (PLEDs). Charge traps in limit the charge transport and thus PLED efficiency. It is firmly established that electron hindered by presence of universal trap density, whereas hole formation governs long-term degradation PLEDs. Here, response PLEDs to electrical driving breaks covering timescale from microseconds (a few) hours studied, focusing on traps. As reference polymer, a phenyl-substituted poly(para-phenylene vinylene) (PPV) copolymer termed super yellow (SY) used. Three different with depths between ?0.4 0.7 eV, total site density ?2 × 1017 cm?3 identified. Surprisingly, filling deep takes minutes hours, at odds common notion trapping complete after few hundred microseconds. The slow feature confirmed using poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene (MEH-PPV) poly(3-hexylthiophene) (P3HT) as active materials. This unusual phenomenon explained deactivation upon detrapping reactivation. results provide useful insight pinpoint chemical nature semiconducting polymers.
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ژورنال
عنوان ژورنال: Advanced Functional Materials
سال: 2022
ISSN: ['1616-301X', '1616-3028']
DOI: https://doi.org/10.1002/adfm.202106185