While the performance of metal halide perovskite light-emitting diodes (PeLEDs) has rapidly improved in recent years, their stability remains a bottleneck to commercial realization. Here, we show that the thermal stability of polymer hole-transport layers (HTLs) used in PeLEDs represents an important factor influencing the external quantum efficiency (EQE) roll-off and device lifetime. We demonstrate a reduced EQE roll-off, a higher breakdown current density of approximately 6 A cm, a maximum radiance of 760 W sr m, and a longer device lifetime for PeLEDs using polymer HTLs with high glass-transition temperatures. Furthermore, for devices driven by nanosecond electrical pulses, a record high radiance of 1.23 MW sr m and an EQE of approximately 1.92% at 14.6 kA cm are achieved. Thermally stable polymer HTLs enable stable operation of PeLEDs that can sustain more than 11.7 million electrical pulses at 1 kA cm before device failure.
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http://dx.doi.org/10.1021/acs.nanolett.3c00148 | DOI Listing |
Macromol Rapid Commun
January 2025
Institute of Polymer Optoelectronic Materials and Devices, Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China.
Simultaneous improvement in power conversion efficiency (PCE) and device stability is very important for organic solar cells (OSCs). Herein, oligothiophene-based polymer W19 with excellent solvent resistance is exploited as a polymer thin layer to optimize the active layer morphology and then device efficiency and stability. Polymer W19 possesses a simple skeleton of trifluromethyl-substituted dithienoquinoxaline and quaterthiophene, whose thin layer shows suitable energy level, low surface energy, and strong interchain aggregation, leading to outstanding solvent resistance and excellent hole transport ability.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Key Laboratory of Functional Molecular Solids, Ministry of Education, School of Chemistry and Materials Science, Anhui Normal University, No.189, Jiuhua South Road, Wuhu, Anhui, 241002, China.
Developing low-cost unipolar n-type organic thin-film transistors (OTFTs) is necessary for logic circuits. To achieve this objective, the usage of new electron-deficient building blocks with simple structure and easy synthetic route is desirable. Among all electron-deficient building units, N-oxide-functionalized bipyridines can be prepared through a simple oxidized transformation of bipyridines.
View Article and Find Full Text PDFMacromol Rapid Commun
January 2025
State Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Special Function Materials and Structure Design, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China.
Conjugated polymers have attracted extensive attention as semiconducting materials in wearable and flexible electronics. In this study, we utilize atom-economical Knoevenagel reaction to construct two conjugated polymers, PTDPP-CNTT and PFDPP-CNTT, based on dialdehyde-thiophene/furan-flanked diketopyrrolopyrrole (DPP) and 2,2'-(thieno[3,2-b]thiophene-2,5-diyl)diacetonitrile (CNTT). The resulting polymers exhibited suitable highest occupied molecular orbital/lowest unoccupied molecular orbital (HOMO/LUMO) energy levels, small bandgaps, and broad UV-vis-NIR absorptions (≈400-1000 nm), endowing them with photothermal and balanced ambipolar semiconducting properties with hole and electron mobilities over 10 cmVs.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Semiconductor Engineering, Gyeongsang National University, Jinjudae-ro 501beon-gil, Jinju-si, Gyeongsangnam-do, Republic of Korea.
Organic photodetectors (OPDs) are cheaper and more flexible than conventional photodetectors based on inorganic precursors, but their wider commercial application is limited by their low electron extraction efficiency under reverse bias conditions (when operating under photoconductive mode). Zinc oxide (ZnO) has shown promise as an electron transport layer for OPDs owing to its wide band gap, but its electron extraction efficiency has been limited by issues such as photoinstability and the formation of surface detects. This study investigated the effects of doping ZnO nanoparticles with indium gallium (i.
View Article and Find Full Text PDFSmall
January 2025
Department of Physics, Pukyong National University, Busan, 48513, Republic of Korea.
Improving the interface characteristics between the hole-transport layer (HTL) and perovskite absorber layer is crucial for achieving maximum efficiency in inverted perovskite solar cells (PSCs). This paper presents an effective functional compensation layer (FCL) composed of benzothiophene derivatives, particularly 5-(trifluoromethyl)-1-benzothiophene-2-carboxylic acid (TFMBTA); this layer is introduced between the MeO-2PACz HTL and perovskite absorber layer to improve the interfacial characteristics between them. This FCL improves charge transfer, hole extraction, and perovskite deposition by improving the surface morphology of the HTL and optimizing the energy level alignment.
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