Highly efficient near-infrared emission from binuclear cyclo-metalated platinum complexes bridged with 5-(4-octyloxyphenyl)-1,3,4-oxadiazole-2-thiol in PLEDs

The luminescence properties of multinuclear platinum complexes

“…Symmetrical (N^C* = N^C) and asymmetrical (N^C* ≠ N^C) complexes of type 36 reported by Thompson and coworkers [58], and the heterometallic Ir-Pt 37 synthesised by Bruce and co-workers for liquid crystalline properties [59]. refer to the complex doped into a thin film; 39, 40 [65], 41 [67], 42 [63,64], 43 [68], 44 [63,64], 45 [68], 46 [69], 47 [70].…”

“…The red-shift that accompanies the shortening of the intermetallic distance is consistent with a 3 MMLCT assignment, since the highest filled dσ* orbitals will be raised as the interaction between the Pt ions becomes stronger.More recently, a number of groups have turned their attention to related bridged dinuclear structures featuring cyclometallated Pt(N^C) units in place of Pt(N^N), which has led to some brightly emissive systems in solution. A selection of these compounds are shown in Fig.20with key photophysical data[63,64,65,66,67,68,69,70]. ‡ They have generally been prepared from the readily accessible chloro-bridged precursors of type [Pt(N^C)(µ-Cl)] 2 or from Pt(N^C)Cl(HN^C) mononuclear complexes.…”

Achieving High-Performance Solution-Processed Orange OLEDs with the Phosphorescent Cyclometalated Trinuclear Pt(II) Complex

“…The peak efficiencies are significantly increased up to 10.5%, 21.4 cd A –1 , and 12.9 lm W –1 and can still remain as high as 10.1%, 20.5 cd A –1 , and 9.4 lm W –1 , respectively, at a high luminescence of 1000 cd m –2 . To the best of our knowledge, this is the best performance ever reported for OLEDs using dinuclear Pt­(II) complexes as emitters. − ,− The most exciting result is that the device based on the trinuclear Pt­(II) complex TPt achieves unexpected high peak efficiencies of 17.0%, 35.4 cd A –1 , and 27.2 lm W –1 with very low efficiency roll-off at a high luminescence of 1000 cd m –2 . This is a benchmark for OLEDs based on trinuclear Pt­(II) complexes .…”

Phosphorescent Molecularly Doped Light‐Emitting Diodes with Blended Polymer Host and Wide Emission Spectra

“…PVK was also a high molecular weight material, which was helpful in forming thin dense films with high uniformity and improving the film-forming quality for the emitting layer and finally improving the stability of device. The HOMO and LUMO level of PFO were estimated to be 5.8 eV and 2.1 eV [ 22 ], so that the wide band gap (3.7 eV) of PFO made it difficult to form ohm contacts for free carriers injecting into emission layer, which was unsuitable to obtain high efficiency device. In order to decrease the LUMO energy level barrier and promote electron transporting ability, 30 wt% PBD was mixed to form blended host matrix.…”