Quantum dots (QDs) light-emitting diodes (QLEDs) are gaining significant interest for the next generation of display and lighting applications because of their wide color gamut, cost-effective solution processability, and good stability. The last decades have witnessed rapid advances in improving their efficiency and lifetime. So far, among the three primary colors of QLEDs devices, the performance of blue QLEDs is considerably inferior to that of green and red ones including Cd-based and Cd-free devices, which is a key bottleneck hindering QLEDs' application.
View Article and Find Full Text PDFThe performance of blue quantum dot light-emitting diodes (QLEDs) is limited by unbalanced charge injection, resulting from insufficient holes caused by low mobility or significant energy barriers. Here, we introduce an angular-shaped heteroarene based on cyclopentane[]thiopyran (C-SS) to modify the hole transport layer poly--vinylcarbazole (PVK), in blue QLEDs. C-SS exhibits high hole mobility and conductivity due to the π···π and S···π interactions.
View Article and Find Full Text PDFBlue quantum dot (QD) light-emitting diodes (QLEDs) exhibit unsatisfactory operational stability and electroluminescence (EL) properties due to severe nonradiative recombination induced by large numbers of dangling bond defects and charge imbalance in QD. Herein, dipolar aromatic amine-functionalized molecules with different molecular polarities are employed to regulate charge transport and passivate interfacial defects between QD and the electron transfer layer (ETL). The results show that the stronger the molecular polarity, especially with the -CF groups possessing a strong electron-withdrawing capacity, the more effective the defect passivation of S and Zn dangling bonds at the QD surface.
View Article and Find Full Text PDFZinc oxide nanoparticles (ZnO NPs) have been actively pursued as the most effective electron transport layer for quantum-dot light-emitting diodes (QLEDs) in light of their unique optical and electronic properties and low-temperature processing. However, the high electron mobility and smooth energy level alignment at QDs/ZnO/cathode interfaces cause electron over-injection, which aggravates non-radiative Auger recombination. Meanwhile, the abundant defects hydroxyl group (-OH) and oxygen vacancies (O) in ZnO NPs act as trap states inducing exciton quenching, which synergistically reduces the effective radiation recombination for degrading the device performance.
View Article and Find Full Text PDFTo date, all the lead halide based full-inorganic or organic-inorganic hybrid perovskites have been synthesized from organic solvent, such as N,N-dimethylformamide (DMF) or dimethyl sulfoxide (DMSO), by a solution method. Herein, water has been utilized as a 'green' solvent to develop an efficient synthetic route to grow various kinds of lead halide perovskite nanowires (NWs). By controlling the proportion of the hybrid cations, Cs(CHNH)PbI perovskite NWs were successfully synthesized.
View Article and Find Full Text PDFUnlabelled: Semitransparent solar cells are highly attractive for application as power-generating windows. In this work, we present semitransparent perovskite solar cells that employ conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (
Pedot: PSS) film as the transparent counter electrode. The
Pedot: PSS electrode is prepared by transfer lamination technique using plastic wrap as the transfer medium.
A new strategy for preparing luminescent and intelligent gold nanodots based on supramolecular self-assembly is described in this paper. The supramolecular self-assembly was initiated through electrostatic interactions and ion pairing between palmitic acid and hyperbranched poly(ethylenimine). The resulting structures not only have the dynamic reversible properties of supramolecules but also possess torispherical and highly branched architectures.
View Article and Find Full Text PDF