Solution‐Processed Highly Efficient Blue Phosphorescent Polymer Light‐Emitting Diodes Enabled by a New Electron Transport Material

Star‐Shaped Macromolecules with the Core of Hexakis‐(fluoren‐2‐yl)benzene and the Periphery of Pyridine: Synthesis and Application as Solution‐Processable Electron‐Transport Materials

“…This work provided a synthetic strategy for the hexaarylbenzene compounds with different positions of pyridine as the periphery units. All the intermediates and the fi nal products were identifi ed by 1 H NMR, 13 C NMR, MALDI-TOF, and elemental analysis, and the data were all in good agreement with designed structures. All the star-shaped compounds exhibited good solubility in common solvents, such as dichloromethane, toluene, and chlorobenzene.…”

“…In these devices, PEDOT:PSS4083 (PEODT:PSS = 1:6) was used as hole-injecting layer; poly(N-vinylcarbazole) (PVK) and 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) were employed as the mixed hosts, and (EtPy) 2 Ir(acac) was used as the orange-red phosphor ( Figure S15, Supporting Information); 3Py-HFB or 4Py-HFB served as ETMs by spincoated from formic acid (FA)/water (H 2 O) mixed solvent (FA:H2O = 3:1) on to the EML. [ 13 ] It is noteworthy that all the layers were fabricated by solution processes. The current effi ciency and current density-voltage-luminance ( J -V -L ) characteristics of the two devices are shown in Figure 3 , and all device data were summarized in Table 3 .…”

Highly efficient blue and all-phosphorescent white polymer light-emitting devices based on polyfluorene host

“…Due to a suppressed phosphorescent quenching by using PVK as the anode buffer layer, a high LE of 26.4 cd A À1 , which is one of the best results based on conjugated polymer reported to date [11][12][13][14][15][16][17] was achieved. More importantly, as compared with the devices based on the non-conjugated host polymer PVK, the devices based on polyfluorene host showed a lower turn-on voltage (3.6 V vs. 4.4 V) and higher PE (17 lm W À1 vs. 8.3 lm W À1 ).…”

“…Huang et al reported that by using Li 2 CO 3 -doped poly [9,9-bis(2-(2-(2-diethanol-aminoethoxy) ethoxy) ethyl) fluorene-alt-4, 4 0 -phenylether] (PDFPE) as the electron transporting layer and p-doped poly (3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) as hole transporting layer, blue-emitting phosphorescent PLEDs based on PVK: FIrpic exhibited a maximal LE of 20.3 cd A À1 and PE of 9.2 lm W À1 [13]. With similar strategy, the efficiency of the blue-emitting phosphorescent PLEDs from PVK: FIrpic have been improved to 22-28 cd A À1 , via doping the active layer with electron transporting molecules or incorporation of small-molecule based electron-transport layer [14][15][16][17]. Despite the progress in the LE of these devices, their power efficiency are relatively low (i.e.…”

High Solid State Photoluminescence Quantum Yields and Effective Color Tuning in Polyvinylpyridine Based Zinc(II) Metallopolymers

“…through chemical synthesis. [1][2][3][4][5][6][7][8] Among these materials polymers containing transition metal complexes (metallopolymers) are an important class whose electron rich ligands and metal centers can enhance optical and electronic properties. [9][10][11][12][13] In the last years our research group focused interest [14][15][16] on O,N ligands with functional substituents able to coordinate a d 10 transition metal ion like Zn(II) into stable chelate complexes with interesting photoluminescence performances.…”