Genetic algorithm-assisted combinatorial chemistry (GACC) was implemented to search for new blue phosphors in seven cation systems, including CaO, MgO, BaO, SrO, B 2 O 3 , P 2 O 5 , and Eu 2 O 3 . The GACC process was followed by a series of fine-tuning processes based on conventional high-throughput screening employing quaternary and ternary libraries, to pinpoint promising compositions. GACC was found to be useful as a preliminary step for final screening. This series of processes involving computations and actual syntheses led us to (Sr 1-x-y Ca x Ba y ) 2 P 2 O 7 :Eu 2+ (0.32 < x < 0.72, y < 0.04) phosphors. It was found that the boron addition played a significant role in enhancing the luminance but it was completely evaporated during the synthesis, and an excessive amount of alkali earth elements was essential for better luminescence. The luminance of (Sr 1-x-y Ca x Ba y ) 2 P 2 O 7 :Eu 2+ (0.32 < x < 0.72, y < 0.04) phosphors reached 70% of a commercially available BAM phosphor at 254 nm excitation. The color chromaticity was in the deep blue region, x ) 0.15, y ) 0.05. The structure of these phosphors was found to be Sr 2 P 2 O 7 (Pnma, 62), but the luminescent property was far better than the Sr 2 P 2 O 7 :Eu 2+ phosphor.

Transparent heaters have attracted increasing attention for their usefulness in vehicle windows, outdoor displays, and periscopes. We present high performance transparent heaters based on Ag nanowires with electron beam irradiation. We obtained an Ag-nanowire thin film with 48 ohm/sq of sheet resistance and 88.8% (substrate included) transmittance at 550 nm after electron beam irradiation for 120 sec. We demonstrate that the electron beam creates nano-soldering at the junctions of the Ag nanowires, which produces lower sheet resistance and improved adhesion of the Ag nanowires. We fabricated a transparent heater with Ag nanowires after electron beam irradiation, and obtained a temperature of 51 °C within 1 min at an applied voltage of 7 V. The presented technique will be useful in a wide range of applications for transparent heaters.

The main objective of the present investigation was to increase the photoluminescence and color chromaticity of Sm2+ -doped Sr-borate phosphors by adding co-dopants. Among the co-dopants used, which included Ce, Mn, Eu, Mg, Zn, Ca, and Ba, the co-doping of europium and samarium was effective in improving the luminescence and color chromaticity of Sr1−xSmxnormalB4normalO7 under excitation at 254nm . The photoluminescence spectrum of the Sr1−xSmxnormalB4normalO7 phosphor showed a peak corresponding to Sm3+ ions at 595nm , and another for Sm2+ ions at 686nm under 254nm excitation even after a strong reduction process. Eu2+ ion co-doping increased the intensity of the Sm2+ peak and eliminated the Sm3+ peak. Thus, the europium co-doping shifted the luminescence to a deep red region. In addition, energy transfer between Eu2+ and Sm2+ was also investigated in detail.

We have investigated the electrical, optical, and structural properties of p-type nitrogen (N)-doped Cu 2 O thin films prepared at various nitrogen gas flow rates for application in heterojunction solar cells. The N-doped Cu 2 O thin films were fabricated by facing-target reactive sputtering. The hole concentration of the N-doped Cu 2 O thin films was affected by N 2 gas flow rate. With increasing N 2 gas flow rate from 0 to 0.5 sccm, the hole concentration and mobility of N-doped Cu 2 O films increased sharply. The resistivity, hole concentration, and mobility of the N-doped Cu 2 O films prepared at a N 2 gas flow rate of 4 sccm were 1.9 Ω&cm, 2.0 ' 10 18 cm %3 , and 3.4 cm 2 &V %1 &s %1 , respectively. The N-doped Cu 2 O films showed Cu 2 O(111) and Cu 2 O(200) diffraction peaks. Cu 2 O(200) diffraction peak intensity increased slightly with N 2 gas flow rate. The Cu 2 O(200) peaks were stronger at a N 2 gas flow rate of 4 sccm than at other gas flow rates.

Spark plasma sintering ͑SPS͒ was employed to synthesize Sr 2 SiO 3.5 N 0.333 :Eu 2+ , Sr 2 SiO 3 N 0.667 :Eu 2+ , and Sr 2 SiO 2 N 1.333 :Eu 2+ for use in white light emitting diodes ͑LED͒ lightings. The SPS technique enabled a complete, rapid synthesis of these phosphors with ease, whereas it is difficult to produce nitridosilicate phosphors by any other conventional synthesis methods. The photoluminescent ͑PL͒ spectrum of Sr 2 SiO 3.5 N 0.333 :Eu 2+ had two emission peaks, one at 420 and the other at 526 nm. There existed a single peak at 529 nm in the case of Sr 2 SiO 3 N 0.667 :Eu 2+ . The PL spectrum of Sr 2 SiO 2 N 1.333 :Eu 2+ also had two peaks, one at 529 and the other at 600 nm. Even though the exact structure was not identified, it was revealed that the X-ray diffraction pattern of Sr 2 SiO 3.5 N 0.333 :Eu 2+ , Sr 2 SiO 3 N 0.667 :Eu 2+ , and Sr 2 SiO 2 N 1.333 :Eu 2+ was consistent with the PL data. The phosphor with the highest nitrogen content, Sr 2 SiO 2 N 1.333 :Eu 2+ , showed a broad emission band spanning almost the entire visible range, which may work best if coupled with either UV or blue LEDs.