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To find an array of suitable materials for phosphorescent organic light‐emitting diodes (OLEDs), in this paper, we design six blue‐green phosphorescent Ir (III) complexes that have low‐efficiency roll‐off properties. Density functional theory and time‐dependent density functional theory were used to study the properties of (2‐[4‐phenoxyphenyl]pyridine [oppy])2Ir(acetylacetonate [acac]), (oppy)2Ir(picolinate [pic]), (oppy)2Ir(tetraphenylimido‐diphosphinate [tpip]), (5‐fluoro‐2‐(4‐phenoxyphenyl)pyridine [F‐oppy])2Ir(acac), (F‐oppy)2Ir(pic), and (F‐oppy)2Ir(tpip). Here, the main ligands are oppy and F‐oppy, while the auxiliary ligands are acac, pic, and tpip. The advantages of these complexes were analyzed in terms of electronic structure, frontier molecular orbital properties, spectral properties, and OLED display effect. We hope that our research will contribute to the development of the OLED industry. [ABSTRACT FROM AUTHOR]

Here, eight phosphorescent heteroleptic cyclometalated Ir (III) complexes were theoretically designed to identify some suitable organic light‐emitting diode materials. (F2‐PYBPY)2Ir (acac) (marked 1), (F2‐PYBPY)2Ir (tpip) (marked 2), (PYBPY)2Ir (acac) (marked 3), (PYBPY)2Ir (tpip) (marked 4), (F2‐PYPY)2Ir (acac) (marked 5), (F2‐PYPY)2Ir (tpip) (marked 6), (PYPY)2Ir (acac) (marked 7), and (PYPY)2Ir (tpip) (marked 8) were studied via density functional theory (DFT) and time‐dependent density functional theory (TD‐DFT) methods. Here, acac denotes acetylacetonate, tpip denotes tetraphenylimido‐diphosphinate, F2‐PYBPY denotes 3‐(4‐tert‐butylpyridin‐2‐yl)‐2,6‐difluoropyridine, PYBPY denotes 4‐tert‐butyl‐2‐(pyridin‐3‐yl) pyridine, F2‐PYPY denotes 2,6‐difluoro‐3‐(pyridin‐2‐yl) pyridine, and PYPY denotes 2‐(pyridin‐3‐yl) pyridine. Further, we discuss the value of these materials from the electronic structure, spectral properties, ionization potentials, electron affinities, and application prospects of the complexes. We hope that these light‐emitting materials contribute to the organic light‐emitting diode sector. This theoretical study included the energy transfer mechanism of the complexes with acac and tpip substituents as auxiliary ligands: We analyzed the possibilities and inevitability of the results in the experiments as well as evaluated the underlying mechanism for these materials' low‐efficiency roll‐off. [ABSTRACT FROM AUTHOR]

Here six phosphorescent heteroleptic cyclometalated Ir (III) complexes were theoretically designed to identify some suitable OLED materials. (fppzb)2Ir(acac), (fppzb)2Ir(tpip), (dfbdp)2Ir(fppzb), (F-fppzb)2Ir(acac), (F-fppzb)2Ir(tpip), and (dfbdp)2Ir(F-fppzb) were studied via density functional theory (DFT) and time-dependent density functional theory (TD-DFT) methods. Here, acac denotes acetylacetonate, tpip denotes tetraphenylimido-diphosphinate, fppzb denotes 4-tert-butyl-2-(5-(trifluoromethyl)-4H-pyrazol-3-yl) pyridine and F-fppzb denotes 4-tert-butyl-2-(5-fluoro-4H-pyrazol-3-yl) pyridine. Further, we discuss the value of these materials from the electronic structure, spectral properties, ionisation potentials, electron affinities, and application prospects of the complexes. We hope that these light-emitting materials contribute to the OLED sector. This theoretical study included the energy transfer mechanism of the complexes with acac and tpip substituents as auxiliary ligands: We analyzed the possibilities and inevitability of the results in the experiments as well as evaluated the underlying mechanism for these materials' low-efficiency roll-off. [ABSTRACT FROM AUTHOR]