Microlasers hold great promise for the development of photonics and optoelectronics. Among the discovered optical gain materials, colloidal quantum dots (CQDs) have been recognized as the most appealing candidate due to the facile emission tunability and solution processability. However, to date, it is still challenging to develop CQD-based microlasers with low cost yet high performance.
View Article and Find Full Text PDFA blue (ca. 440 nm) liquid laser with an ultra-low threshold through which quasi-continuous wave pumping is accessible is achieved by engineering unconventional ternary CdZnS/ZnS alloyed-core/shell QDs. Such an achievement is enabled by exploiting the novel gain media with minimal defects, suppressed Auger recombination, and large gain cross-section in combination with high-quality-factor whispering gallery mode resonators.
View Article and Find Full Text PDFAn efficient and stable quantum dot light-emitting diode (QLED) with double-sided metal oxide (MO) nanoparticle (NP) charge transport layers is fabricated by utilizing the solution-processed tungsten oxide (WO3) and zinc oxide (ZnO) NPs as the hole and electron transport layers, respectively. Except for the electrodes, all other layers are deposited by a simple spin-coating method. The resulting MO NP-based QLEDs show excellent device performance, with a peak luminance of 21300 cd/m(2) at the emission wavelength of 516 nm, a maximal current efficiency of 4.
View Article and Find Full Text PDFA highly efficient and stable QLED using an inorganic WO3 nanoparticle film as a hole injection layer is demonstrated.The resulting WO3 nanoparticle-based QLEDs also exhibit superior performance compared to that of the present PEDOT:PSS-based QLEDs. The results indicate that WO3 nanoparticles are promising solution-processed buffer layer materials and serve as a strong candidate for QLED technology towards the practical applications in the next-generation lighting and displays.
View Article and Find Full Text PDFACS Appl Mater Interfaces
July 2013
Two novel heteroacenes 2,3,9,10-tetra(furan-2-yl)-1,4,8,11-tetraaza-6,13-dioxapentacene (FAOP, 1) and 2,3,9,10-tetra(thiophen-2-yl)-1,4,8,11-tetraaza-6,13-dioxapentacene (TAOP, 2) was successfully synthesized through a one-step condensation reaction, which have been fully characterized by (1)H NMR (nuclear magnetic resonance), (13)C NMR, FT-IR (Fourier transform infrared spectroscopy), and HRMS (high-resolution mass spectrum). The sandwich-structure memory devices have been fabricated using FAOP (1) and TAOP (2) as active layers, showing a typical bipolar resistive switching (RS) behavior in positive and negative regions.
View Article and Find Full Text PDFACS Appl Mater Interfaces
July 2013
We report a hybrid, quantum dot (QD)-based, organic light-emitting diode architecture using a noninverted structure with the QDs sandwiched between hole transporting layers (HTLs) outperforming the reference device structure implemented in conventional noninverted architecture by over five folds and suppressing the blue emission that is otherwise observed in the conventional structure because of the excess electrons leaking towards the HTL. It is predicted in the new device structure that 97.44% of the exciton formation takes place in the QD layer, while 2.
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