Star‐Shaped Phenanthroimidazole‐Triphenylamine‐Based Yellow Organic Emitter for Organic Light Emitting Diodes. Issue 8 (22nd March 2017)

• Record Type: Journal Article
• Authors: Tagare, Jairam; Ulla, Hidayath; Kajjam, Aravind Babu; Satyanarayan, M.N.; Vaidyanathan, Sivakumar
• Is Part Of: ChemistrySelect. Volume 2:Issue 8(2017)
• Page Start: 2611
• Page End: 2620
• Publication Date: 2017-03-22
• Subjects: High-efficiency -- Organic light emitting diodes (OLED) -- TPA derivative -- TD-DFT -- Undoped OLED; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201700056
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: In this work, new star‐shaped conjugated organic emitter, namely tris(4‐(1‐(9, 9‐diethyl‐9H‐fluoren‐2‐yl)‐1H‐phenanthro[9, 10‐d]imidazol‐2‐yl)phenyl)amine (PIFTPA) with donor‐π‐acceptor (D‐π‐A) structure, was designed and synthesized by combining three fluoren‐phenanthroimidazole arms into a triphenylamine core and characterized using 1 H, 13 C NMR and mass spectrometry. The detailed photophysical, thermal, electrochemical and electroluminescence properties were systematically studied. The organic emitter exhibits high glass transition temperature (230 °C) and high thermal stability with decomposition temperature. Electrochemical analysis reveals that the emitter has distinct oxidation and reduction behaviours. Furthermore, theoretical calculations (DFT) were performed to get a better understanding of the electronic structure. The OLEDs using this emitter as emissive material showed good device performance (6.45 cd/A, 4.39 lm/W, and 3.01%) with yellow emission and a low turn‐on voltage (2.87 V). The results demonstrate that TPA integrated with phenthroimdazole plays an important role in the device performance. Abstract : Non‐doped organic light‐emitting devices (OLEDs) using these emitter as emissive material display yellow emission with high efficiency, low turn‐on voltages and excellent spectral stability.