Hole‐buffer polymer composed of alternating p‐terphenyl and tetraethylene glycol ether moieties: Synthesis and application in polymer light‐emitting diodes

Abstract

Carrier balance is essential to obtain efficient emission in polymer light-emitting diodes (PLEDs). A new polymer 3P5O composed of alternating p-terphenyl and tetraethylene glycol ether segments is designed and synthesized by the Suzuki coupling reaction and successfully employed as hole-buffer layer to improve carrier balance. Multilayer PLEDs [ITO/ PEDOT:PSS/3P5O/SY/LiF/Al], with Super Yellow (SY) as the emitting layer and 3P5O as the hole-buffer layer, reveal maximum luminance (17,050 cd/m 2 ) and maximum current efficiency The performance enhancement has been attributed to holebuffering characteristics of 3P5O that results in improved carrier recombination ratio and wider carrier recombination region. Current results indicate that the 3P5O is a promising hole-buffer polymer to enhance the performance of optoelectronic devices.

Bulk Organic Doped p-Terphenyl Crystals for X-ray Scintillators with Low Detection Limit, Nanoseconds Decay Time, and Tunable Fluorescence

“…p -Terphenyl, an organic scintillation material, is frequently employed as the luminescent material in scintillation counters . Research indicates that p -terphenyl, as a scintillation material, possesses excellent scintillation properties such as high light output, rapid scintillation response, and good energy resolution. − This suggests that p -terphenyl can effectively serve as a sensitizer for high-energy radiation, converting it efficiently to photon energy. The photon energy excites the dopants through energy transfer, resulting in distinct luminescent characteristics.…”

Flow reactor synthesis of unsymmetrically substitutedp-terphenyls using sequentially selective Suzuki cross-coupling protocols

“…Besides their use in biology and medicine, terphenyl and poly-phenyl compounds have found other important applications, as liquid crystals and fluorescent optoelectronic compounds (18). Functionalized terphenyls, based on di-or tri-amino-1,1 ′ :3 ′ ,1 ′′ -terphenyls, have, for example, been used in charge transporting/ charge generating agents (19,20), metal organic frameworks (21), conducting polymers (22,23), and light emitting diodes (24), whilst the photo-physical properties of o-, m-, and p-terphenyl compounds have been exploited in organic liquid-crystalline materials and organic electroluminescent (OEL) devices by taking advantage of the different organizational arrangements of the aromatic rings in the two dimensional plane (18,25).…”

Hole-Buffer Material Derived from Pyrene, Schiff Base and Tris to Enhance Emission Efficiency of Polymer Light-Emitting Diodes

“…For instance, copper (II) phthalocyanine (CuPC), and 4,4',4''-tris (N-carbazolyl)-triphenylamine (TATC) were deposited as hole-buffering layer which effectively reduced hole mobility [14] [15]. We have designed a polymer 3P 5 O composed of alternating p-terphenyl and tetraethylene glycolether segments and successfully employed as hole-bufferlayer to improve carriers balance [16]. The hole buffer layer was inserted between hole injection and emissive layers, it reduces the mobility of holes and thus recombine with electrons in the whole emissive layer, leading to enhanced device performance [16] [17].…”

“…We have designed a polymer 3P 5 O composed of alternating p-terphenyl and tetraethylene glycolether segments and successfully employed as hole-bufferlayer to improve carriers balance [16]. The hole buffer layer was inserted between hole injection and emissive layers, it reduces the mobility of holes and thus recombine with electrons in the whole emissive layer, leading to enhanced device performance [16] [17]. In 1999, Forsythe found that transport of holes from ITO anode to NPB hole-transporting layer was injection-limited and device performance depended on hole current [18].…”