Pyrene-based hyperbranched porous polymers with doped Ir(piq)2(acac) red emitter for highly efficient white polymer light-emitting diodes

Abstract

Here, we designed and prepared a series of hyperbranched porous polymers constructed using fluorene branches and pyrene core, and all hyperbranched porous polymers exhibit intense blue fluorescence, good morphological stability, and high thermal stability. Further, it is found that the aperture sizes for hyperbranched porous polymers can be adjusted by simply changing the content of pyrene and fluorene in the synthesis process. When the feed ratios of pyrene in the total polymers is 15 mol%, the optimized aperture size was obtained, which is slightly larger than the maxlength of complementary red emitter Bis(1phenylisoquinoline)(acetylacetonate) iridium (III) (Ir(piq)2acac), indicating the Ir(piq)2acac can well distributed in the apertures of hyperbranched porous polymers in co-doped film of Ir(piq)2acac and hyperbranched porous polymers. The fabricated polymer-light-emitting diode (PLED) with such co-doped film as light-emitting layer realizes good white emission with almost equal blue and red emission intensity from hyperbranched porous polymers and Ir(piq)2acac. The balanced electroluminescent (EL) spectra contribute to ideal Commission Internationale de l'Eclairage (CIE) coordinate of (0.326, 0.374) located at white light zone. In addition, the device also achieves high device performance with maximum luminance and current efficiency reaching 5369 cd/m 2 and 8.35 cd/A, respectively. We believe that such porous-structure polymers have huge potential applications in the development of highly efficient white PLEDs with reducing production cost.

Organometallic Coatings for Electroluminescence Applications

“…The obtained values vary between 3819 and 5369 cd/m 2 for 11 V applied bias, the current efficiency between 3.96 and 8.35 cd/A and the power efficiency between 1.28 and 3.09 lm/W for 35 nm organometallic neat films. [60]. In the case of Ir(ppy) 2 (acac), the turn-on voltage is around 2.4 V, while for electroluminescence of 10,000 cd/m 2 , the power efficiency is about 96 lm/W, which is much better than in our case [61].…”

Synthesis and properties of hyperbranched polymers for white polymer light-emitting diodes

“…In these devise, ITO and Al are used as anode and cathode, respectively; PEDOT:PSS and TPBi are used as hole transport layer and electron transport layer, respectively; 50 nmthick polymers layer is used as EML, and 1 nm-thick LiF layer used as electron injection layer. 1,[31][32][33][34][35] Fig . 6a-d shows the EL spectra for all polymers-based PLEDs at voltages varying from 7 to 11 V. It can be seen that all resulting PLEDs with PFCzSDF10Ir6, PFCzSDF10Ir7, PFCzSDF10Ir8, PFCzSDF10Ir9 as realize good white emission with CIE coordinate of at (0.27,0.25), (0.27,0.24), (0.26,0.30), and (0.27,0.31) at 11 V, respectively, and the EL spectra for these PLEDs all contain two main emission peaks located at blue and orange-red wavebands, which are corresponding to the emissions of poly(uorene-altcarbazole) branches and red dimming phosphor group (Ir(piq) 2acac).…”

White Light from Dual Intramolecular Charge-Transfer Emission in a Silylene-Bridged Styrylcarbazole and Pyrene Dyad

“…The components of the chosen dyad (carbazole derivative and pyrene) were selected because they play a pivotal role in many areas of photophysics and optoelectronics. − These popular polycyclic aromatic hydrocarbons and their various derivatives (including silicon-based carbazole ,− and pyrene-containing compounds − ) have found application in optoelectronics, solar cells, TADF and organic light-emitting diode (OLED) materials, or fluorescent probes for elucidation of the geometries of various biomolecules. , There are also interesting studies that report white-light emission from pyrene-based compounds, − and many of them are related to aggregation-induced emission. Furthermore, there are known examples of carbazole–pyrene hybrid compounds for dye-sensitized solar cell applications, OLEDs, − and electroluminescent devices …”