The cathodoluminescent characteristics (CL) of a spherical Y 2 O 3 :Eu phosphor screen were investigated for field emission display application. The phosphor screen as an anode plate was vacuum sealed (ϳ3 ϫ 10 Ϫ6 Torr) with 0.7 in. diagonal Si-based Mo tip field emitter array with 25 ϫ 25 pixels. It was prepared by electrophoretically depositing spherical Y 2 O 3 :Eu phosphors, which were synthesized by the aerosol pyrolysis method. The character image was displayed on this anode plate by an external driver circuit with PWM driving scheme. The CL brightness of 41 cd/m 2 with CIE chromaticity of x ϭ 0.649, y ϭ 0.346 could be obtained at 400 V anode voltage and 55 V gate voltage inducing a 48 A/cm 2 current density in the dc mode, corresponding to 0.63 lm/W. However, screen efficiency could be increased to 1.24 lm/W by reducing the charge dose on the screen, of which the operating conditions were of 400 V anode voltage and 60 Vp-p gate voltage inducing an average 30 A/cm 2 emission current density in 15% pulse mode. It was found that the electrical resistivity of the phosphor screen was the origin of a pool image of displayed character and even caused a sudden decrease of emission light. The charging effects of spherical Y 2 O 3 :Eu phosphors screen on the luminance under low voltage operation are examined in this work and the methodology for enhancing picture quality is discussed based on experimental observation.

Dynamic particles with switchable shapes in response to light have attracted great interest to develop programmable smart materials with superior spatial and temporal resolution. Herein, a facile strategy for light-responsive, shape-changing block copolymer (BCP) particles is developed. Key to this strategy is the design of azobenzene-grafted Au nanoparticles (Au@Azo NPs) as photoswitchable surfactants through photoisomerization of Azo ligands. Under visible light, onion-like polystyrene-block-poly­(2-vinylpyridine) (PS-b-P2VP) BCP particles with PS outer layer form due to the nonpolar nature of trans-Azo ligands, whereas the isomerization to polar cis-Azo surfactants with UV irradiation transforms these spheres into ellipsoids with both PS and P2VP exposed on their surfaces. This light-driven shape change is robust and reversible over multiple irradiation cycles. The reversible shape evolution between spherical and ellipsoidal BCP particles induced by photoactive Au@Azo NP surfactants is elucidated using a cryogenic electron microscope. Furthermore, light-dependent fluorescence and shape of the BCP particles are successfully demonstrated, enabling the visualization of particle shape into an optical signal.

Solid‐state lithium (Li)‐metal batteries (LMBs) are garnering attention as a next‐generation battery technology that can surpass conventional Li‐ion batteries in terms of energy density and operational safety under the condition that the issue of uncontrolled Li dendrite is resolved. In this study, various plastic crystal‐embedded elastomer electrolytes (PCEEs) are investigated with different phase‐separated structures, prepared by systematically adjusting the volume ratio of the phases, to elucidate the structure‐property‐electrochemical performance relationship of the PCEE in the LMBs. At an optimal volume ratio of elastomer phase to plastic‐crystal phase (i.e., 1:1), bicontinuous‐structured PCEE, consisting of efficient ion‐conducting, plastic‐crystal pathways with long‐range connectivity within a crosslinked elastomer matrix, exhibits exceptionally high ionic conductivity (≈10−3 S cm−1) at 20 °C and excellent mechanical resilience (elongation at break ≈ 300%). A full cell featuring this optimized PCEE, a 35 µm thick Li anode, and a high loading LiNi0.83Mn0.06Co0.11O2 (NMC‐83) cathode delivers a high energy density of 437 Wh kganode+cathode+electrolyte−1. The established structure–property–electrochemical performance relationship of the PCEE for solid‐state LMBs is expected to inform the development of the elastomeric electrolytes for various electrochemical energy systems.

A poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene](MEH-PPV) light-emitting diode was coated with passivation layers in order to improve the longevity of conjugated polymer-based diodes. High-density polyethylene (HDPE), which is an insulator, was used as the passivation material in combination with a metal layer to minimize oxygen and water diffusion into the polymer light-emitting diodes. The simplicity of the HDPE(1 μm)/Al–Li(120 nm)/HDPE(1 μm) structure, which was successively thermal coated on the diode, was demonstrated. The longevity of this simple structure was dramatically enhanced after exposure to atmospheric oxygen and moisture.

No abstract