Os(II) Based Green to Red Phosphors: A Great Prospect for Solution-Processed, Highly Efficient Organic Light-Emitting Diodes

Autor: Cheng-Huei Lin, Gang-Lun Fan, Jia-Ling Liao, Pi-Tai Chou, Yun Chi, Gene-Hsiang Lee, Ken-Tsung Wong, Hao-Wu Lin, Hsiao-An Pan, Bo-Sian Du, Ming-Hong Huang
Rok vydání: 2012
Předmět:
Zdroj: Advanced Functional Materials. 22:3491-3499
ISSN: 1616-301X
DOI: 10.1002/adfm.201200718
Popis: Preparation and characterization of a new class of emissive Os(II) complexes (1–5) have been achieved using 3-(thiazol-2-yl), 3-(benzothiazol-2-yl), 3-(imidazol-2-yl) and 3-(benzimidazol-2-yl) azole chelates, together with the incorporation of one diphosphine ancillary for satisfying the octahedral coordination arrangement. The resulting Os(II) complexes, except for 5, all show bright emission spanning visible region from green to saturated red, and their structural versus spectroscopic properties have been comprehended by absorption/emission together with computational approaches. Subsequently, a series of solution-processed OLEDs using 1–4 as the dopant were successfully fabricated, demonstrating excellent device performances with external quantum efficiency (EQE) of 15%, current efficiency exceeding 48 cd/A, and power conversion efficiency up to 50 lm/W. Complex 4 is the only Os(II) based phosphor so far suitable for the fabrication of highly efficient green-emitting OLEDs.
Databáze: OpenAIRE