Publications by authors named "Khaled Al Kurdi"
Article Synopsis
- The study focuses on the synthesis and electrochemical properties of various benzoimidazole compounds, which are being explored as n-dopants in organic electron-transport materials.
- It highlights that 2-aryl substituents stabilize radicals more effectively than 2-alkyl groups, leading to different reactivity patterns in reactions with PCBM and other compounds.
- The findings reveal significant differences in reactivity based on structural modifications, with certain dimers demonstrating faster reaction rates and unique electrochemical characteristics, as confirmed through crystal structure analysis.
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.
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- This study examines the charge transport properties of two polymer films, P3HT and PE, when doped with different iron(III) salts, focusing on how doping affects conductivity and thermoelectric characteristics.
- P3HT shows significant variation in electrical conductivity and Seebeck coefficients depending on the iron(III) anion used, while PE's properties change less due to its lower oxidation onset.
- The SLoT model indicates that PE may be more electrically conductive than P3HT because it achieves greater oxidation levels and shifts in Fermi energy, potentially leading to better performance in applications.
Doping has proven to be a critical tool for enhancing the performance of organic semiconductors in devices like organic light-emitting diodes. However, the challenge in working with high-ionization-energy (IE) organic semiconductors is to find p-dopants with correspondingly high electron affinity (EA) that will improve the conductivity and charge carrier transport in a film. Here, we use an oxidant that has been recently recognized to be a very strong p-type dopant, hexacyano-1,2,3-trimethylene-cyclopropane (CN6-CP).
View Article and Find Full Text PDFWhile metal-halide perovskite light-emitting diodes (PeLEDs) hold the potential for a new generation of display and lighting technology, their slow operation speed and response time limit their application scope. Here, high-speed PeLEDs driven by nanosecond electrical pulses with a rise time of 1.2 ns are reported with a maximum radiance of approximately 480 kW sr m at 8.
View Article and Find Full Text PDFCrystallization from solutions containing 2,2'-[naphthalene-1,8:4,5-bis(dicarboximide)-'-diyl]-bis(ethylammonium) diiodide ((NDIC2)I) and PbI has been investigated. Eight different materials are obtained, either by variation of crystallization conditions or by subsequent thermal or solvent-induced transformations. Crystal structures have been determined for five materials.
View Article and Find Full Text PDFThe performance of lead-halide perovskite light-emitting diodes (LEDs) has increased rapidly in recent years. However, most reports feature devices operated at relatively small current densities (<500 mA cm ) with moderate radiance (<400 W sr m ). Here, Joule heating and inefficient thermal dissipation are shown to be major obstacles toward high radiance and long lifetime.
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