Using light-emitting dyes as a co-host to markedly improve efficiency roll-off in phosphorescent yellow organic light emitting diodes

Dramatic efficiency improvement in single-layer orange phosphorescent organic light-emitting devices with suppressed efficiency roll-off

“…[22][23][24] Ouyang et al have This journal is © The Royal Society of Chemistry 2016 demonstrated the rst time with improved dopant concentration by designing and synthesising an ideal saturated deep-blue uorophore. [22][23][24] Ouyang et al have This journal is © The Royal Society of Chemistry 2016 demonstrated the rst time with improved dopant concentration by designing and synthesising an ideal saturated deep-blue uorophore.…”

“…[22][23][24] Ouyang et al have This journal is © The Royal Society of Chemistry 2016 demonstrated the rst time with improved dopant concentration by designing and synthesising an ideal saturated deep-blue uorophore. 22,23 But there has been no relevant report about the use in single-layer OLEDs. 22,23 But there has been no relevant report about the use in single-layer OLEDs.…”

High efficiency yellow organic light emitting diodes with a balanced carrier injection co-host structure

“…[45][46][47] Amongst, balanced carrier injection has played a very crucial role, especially because imbalanced carrier injection oen accounts for the low efficiency observed in typical OLEDs, which originates from the difficulty in the injection of an electron, making it a minor carrier in many cases. [48][49][50] Apparently, the second approach is preferred as it is able to achieve comparatively higher device efficiency, which explains why there have been intensive studies regarding the development of new electron injection materials, electron transporting materials, and bipolar hosts recently. [48][49][50] Apparently, the second approach is preferred as it is able to achieve comparatively higher device efficiency, which explains why there have been intensive studies regarding the development of new electron injection materials, electron transporting materials, and bipolar hosts recently.…”

Enabling high-efficiency organic light-emitting diodes with a cross-linkable electron confining hole transporting material

“…However, wet-processed devices often show comparatively poor performance 38 due to the lack of solution-process feasible functional materials that exhibit robust mechanical proper- 39 ties. We demonstrate here a cross-linkable material, 3,6-bis(4-vinylphenyl)-9-ethylcarbazole (VPEC), to 40 facilitate the injection of hole and meanwhile effectively confine electron to realize, for examples, high 41 efficiency organic light-emitting diodes, especially at high luminance. The VPEC shows a hole mobility 42 of 1 Â 10 À4 cm 2 V À1 s À1 and a triplet energy of 2.88 eV.…”

“…66 Over the past years, numerous efficiency effective architectural 67 approaches have been proposed. They include the employment 68 of low interfacial resistance P-I-N structures [14-18], low 69 carrier-injection-barriers [19][20][21][22], balanced carrier injection 70 [23-28], carrier and exciton confinement [29][30][31][32][33], stepwise emis- 71 sive layers [34], carrier modulation layers [35][36][37], structures 72 enabling exciton to generate on host or on both host and guest 73 [38], structures facilitating host-to-guest energy transfer [39,40], 74 and co-host structures [41,42], etc. All these approaches are valid 75 for OLED devices fabricated via dry-process, but not all applicable 76 if via wet-process.…”