High Reliability of Ag Reflectors with AgCu Alloy for High Efficiency GaN-Based Light Emitting Diodes.

We propose an Ag reflector layer with an AgCu alloy layer as a thermally reliable reflector for high power flip-chip and vertical light emitting diodes (LEDs). By annealing the deposited Ag and Cu layers, intermixed grains and grain boundaries from the alloyed AgCu layer were formed on the LEDs, and CuO nano dots precipitated at the grain boundaries. A thick AgCu layer was deposited to cover the AgCu alloy layer. The precipitation of the CuO nano dots at the grain boundaries suppressed Ag agglomeration, leading to enhanced light reflectance after the annealing process. Consequently, the alloyed AgCu/Ag reflector produced by annealing at a high temperature of 500 °C demonstrated a higher reflectance of 78% and a lower contact resistance of 7.0 × 10-5 Ω · cm2.

Wide Bandgap Transparent Conducting Electrode of FTO/Ag/FTO Structure for Ultraviolet Light-Emitting Diodes.

We investigated the effect of the Ag interlayer thickness on the structural, electrical and optical properties of FTO/Ag/FTO structures designed for use in wide bandgap transparent conducting electrodes. The top and bottom FTO layers were deposited on α-Al2O3 (0001) substrates via RF magnetron sputtering at 300 °C and Ag interlayers were deposited using an e-beam evaporator system. We optimized the figure of merit by changing the thickness of the inserted Ag interlayer from 10 nm to 14 nm, achieving a maximum value of 2.46 × 10-3 Ω-1 and a resistivity of 6.4 × 10-4 Ω · cm using an FTO (70 nm)/Ag (14 nm)/FTO (40 nm) structure. Furthermore, the average optical transmittance in the deep UV range (300 to 330 nm) was 82.8%.

Inkjet-printing of antimony-doped tin oxide (ATO) films for transparent conducting electrodes.

Antimony-doped Tin oxide (ATO) films have been prepared by inkjet-printing method using ATO nanoparticle inks. The electrical and optical properties of the ATO films were investigated in order to understand the effects of rapid thermal annealing (RTA) temperatures. The decrease in the sheet resistance and resistivity of the inkjet-printed ATO films was observed as the annealing temperature increased. The film annealed at 700 degrees C showed the sheet resistance of 1.7 x 10(3) Omega/sq with the film thickness of 350 nm. The optical transmittance of the films remained constant regardless of their annealing temperatures. In order to further reduce the sheet resistance of the films as well as the annealing temperature, Ag-grid was printed in between two layers of inkjet-printed ATO. With 1.5 mm Ag line spacing, the Ag-grid embedded ATO film showed the sheet resistance of 25.6 Omega/sq after RTA at 300 degrees C.

High throughput detection and selective enrichment of histidine-tagged enzymes with Ni-doped magnetic mesoporous silica.

This work reports a simple and facile method to prepare novel magnetic mesoporous silica (MMS) materials with high magnetic strength for the convenient and high throughput detection of histidine-tagged enzymes with Ni-doped surfaces. These materials are designed by the incorporation of high-abundance and homogeneously dispersed iron nanoparticles within the mesopores by thermal hydrogen reduction after the incorporation of ferrous ions and demonstrated the selective enrichment and high-throughput recognition of His-tagged enzymes with multi-point anchoring by selective conjugation between the His-tag and Ni ions. Selective His-tagged enzyme enrichment efficiency was compared with nickel-based MMS materials, such as Ni2+-MMS and Ni-MMS, and nickel ion doped silica-coated magnetic nanoparticles (Ni2+-MNPs). The efficiency was calculated to be 100 ± 1.93%, 70.94 ± 1.95%, and 37.03 ± 5.93% for Ni2+-MMS, Ni-MMS, and Ni2+-MNPs, respectively. This method enables a high-throughput and advanced systematic approach for the separation and immobilization of proteins which cover a broad spectrum of polyhistidine-tagged proteins.