title: An inconvenient influence of iridium(III) isomer on OLED efficiency.
abstract: The recently reported heteroleptic cyclometallated iridium(III) complex [Ir(2-phenylpyridine)(2)(2-carboxy-4-dimethylaminopyridine)] N984 and its isomer N984b have been studied more in detail. While photo- and electrochemical properties are very similar, DFT/TDDFT calculations show that the two isomers have different HOMO orbital characteristics. As a consequence, solution processed OLEDs made using a mixture of N984 and isomer N984b similar to vacuum processed devices show that the isomer has a dramatic detrimental effect on the performances of the device. In addition, commonly used thermogravimetric analysis is not suitable for showing the isomerization process. The isomer could impact performances of vacuum processed OLEDs using heteroleptic cyclometallated iridium(III) complexes as dopant.
authors: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Swiss Federal Institute of Technology, Station 6, CH-1015, Lausanne, Switzerland. etienne.baranoff@epfl.ch
authors: Etienne
authors: E
authors: Baranoff
authors: Henk J
authors: HJ
authors: Bolink
authors: Filippo
authors: F
authors: De Angelis
authors: Simona
authors: S
authors: Fantacci
authors: Davide
authors: D
authors: Di Censo
authors: Karim
authors: K
authors: Djellab
authors: Michael
authors: M
authors: Grätzel
authors: Md Khaja
authors: MK
authors: Nazeeruddin
mesh_terms: D004563:Electrochemistry; D007495:Iridium / Q000737:chemistry*; D007536:Isomerism; D008027:Light; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D009942:Organometallic Compounds; D007495:Iridium