کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1263964 972093 2013 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Extremely low driving voltage electrophosphorescent green organic light-emitting diodes based on a host material with small singlet–triplet exchange energy without p- or n-doping layer
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Extremely low driving voltage electrophosphorescent green organic light-emitting diodes based on a host material with small singlet–triplet exchange energy without p- or n-doping layer
چکیده انگلیسی

In order to achieve low driving voltage, electrophosphorescent green organic light-emitting diodes (OLEDs) based on a host material with small energy gap between the lowest excited singlet state and the lowest excited triplet state (ΔEST) have been fabricated. 2-biphenyl-4,6-bis(12-phenylindolo[2,3-a] carbazole-11-yl)- 1,3,5-triazine (PIC–TRZ) with ΔEST of only 0.11 eV has been found to be bipolar and used as the host for green OLEDs based on tris(2-phenylpyridinato) iridium(III) (Ir(ppy)3). A very low onset voltage of 2.19 V is achieved in devices without p- or n-doping. Maximum current and power efficiencies are 68 cd/A and 60 lm/W, respectively, and no significant roll-off of current efficiency (58 cd/A at 1000 cd/m2 and 62 cd/A at 10,000 cd/m2) have been observed. The small roll-off is due to the improved charge balance and the wide charge recombination zone in the emissive layer.

Figure optionsDownload as PowerPoint slideHighlights
► Host material with small energy gap between the lowest excited singlet state and the lowest excited triplet state.
► A very low onset voltage of 2.91 V is achieved.
► High efficiency and small roll-off have been observed.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Organic Electronics - Volume 14, Issue 1, January 2013, Pages 260–266
نویسندگان
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