Methoxy-substituted bis-tridentate iridium(iii) phosphors and fabrication of blue organic light emitting diodes

Abstract

Both the monoanionic dicarbene pincer chelate and dianionic azole-pyridine-carbazole cyclometalate were successfully employed in the preparation of respective bis-tridentate Ir(III) metal complexes (Cz6 ‒ 9) in moderate yields. Tuning of...

Rational Tuning of Bis-Tridentate Ir(III) Phosphors to Deep-Blue with High Efficiency and Sub-microsecond Lifetime

“…Hence, only the blue phosphor Dap-5 was employed in the fabrication of OLEDs using the following device architecture: indium tin oxide (ITO)/4 wt % ReO 3 :mCP (60 nm)/mCP (15 nm)/DPEPO: dopant (15 wt.%, 35 nm)/3TPYMB (50 nm)/Liq (0.5 nm)/Al (100 nm). 32 We also varied the doping concentrations of phosphor Dap-5 from 5 to 15 wt % in looking for an optimal performance. The original results and key characteristics are depicted in Table 3 and Figure S11 of the Supporting Information.…”

“…Concurrently, the electroluminescence of previously studied bis-tridentate dopant Cz7 is also presented for a close comparison. 32 Figure 4a shows the schematic energy-level diagram of the device. The HOMO of Dap-5 is located at −5.71 eV which can facilitate the transportation of hole from mCP with a reduced barrier.…”

“…Hence, further structural tuning was executed, giving the fifth Ir(III) complex Dap-5, which is in sharp contrast to a reference complex Cz7 that exhibited a similar color hue but with a much lengthened emission lifetime. 32 Detailed examination on their photophysical properties plus realization of efficient blue phosphorescent OLEDs using Dap-5 will be described and discussed. diamine, followed by reduction of the nitro group in giving an amino substituent.…”

A computational scheme for evaluating the phosphorescence quantum efficiency: applied to blue-emitting tetradentate Pt(ii) complexes

“…[4][5][6] However, the development of highly efficient deep-blue organometallic emitters is still of significant challenge, mainly due to their attainable metal-centered d-d quenching states. 7,8 Recently, a rapid progress has been made in the development of efficient deep-blue OLEDs employing Pt(II) complexes that have met or even exceeded the performance of Ir(III) complexes in many aspects. 9,10 On the one hand, Pt(II) complexes have demonstrated phosphorescence quantum efficiencies (F p ) close to unity and a short luminescence lifetime in the range of microseconds at room temperature, thus making them advantageous as phosphorescent emitters.…”

Tetradentate Platinum(II) and Palladium(II) Complexes Containing Fused 6/6/6 or 6/6/5 Metallocycles with Azacarbazolylcarbazole-Based Ligands

“…Besides the central metal ions, the cyclometalating ligands are also critical to the luminescent metal complexes and have a profound influence on their photophysical properties, chemical stabilities, and thermal stabilities. Because of the rigid octahedral configuration, both tris-bidentate ,− and bis-tridentate − Ir­(III) complexes can show good photophysical properties and demonstrate high device performances. In contrast, Pt­(II) complexes possess planer molecular geometries and usually show low quantum efficiencies for the complexes with bidentate ligands because the flexible molecular geometries lead to structural deformations in their excited states, which increase the electronic–vibrational coupling of the excited and ground states to promote nonradiative decays .…”