Xiaoxia Jiang

Organic photovoltaic cells with near infrared absorption spectrum

Organic photovoltaic cells with a strong absorption spectrum in the near infrared region were fabricated with the structure of indium tin oxide (ITO)/zinc phthalocynine (ZnPc)/lead phthalocynine (PbPc)∕C60∕Al. PbPc has a broad and strong absorption, while the organic films of PbPc∕C60 showed an additional new absorption peak at 900nm. The absorption in the near infrared region can harvest more photons to invert into photocurrent. Moreover, the introduction of ZnPc thin layer between ITO and PbPc further improved the new absorption peak and the collection of hole carriers at the electrode ITO, which increased the power conversion efficiencies to 1.95% and short-circuit current density to 9.1mA∕cm2 under AM 1.5 solar spectrum.

Manufacturing, structure and high temperature corrosion of palladium-modified aluminide coatings on nickel-base superalloy M38

Three palladium-modified aluminide coatings were prepared by conventional pack-cementation aluminizing process on the nickel-based superalloy M38, which was previously electroplated with pure palladium, Pd-20 wt.% Ni alloy, or Pd + Ni composite plating. The structure of all coatings was thoroughly analyzed. A major difference between Pt- and Pd-modified aluminide coatings resided in the fact that the Pd zone was single-phased and the constitutive phase was beta-(Pd-x,Ni1-x)Al. The isothermal oxidation resistance of the Pd-20 wt.% Ni alloy modified coatings was better than that of the other two palladium-containing and conventional aluminide coatings in air at 1000 degreesC. The hot corrosion performance of Pd-Ni-Al coatings was also tested in Na,SO, melt at 900 degreesC. As regards their hot corrosion resistance, they behaved at least as well as commercial Pt-Al coatings under the same testing conditions and remarkably better than conventional aluminide coatings. The behavior of cyclic oxidation of Pd-Ni-Al coating was inspected at 1050 degreesC and its corrosion mechanism was also preliminary discussed

Cyclic oxidation behavior of palladium-modified aluminide coating

(Ni,Pd)AI coating prepared by low-pressure pack cementation on the nickel-base superalloy IN738 predeposited Pd-20 wt.% Ni alloy, and their cyclic oxidation behavior was investigated by TGA, XRD, SEM/EDS and optical microscopy at 1050 degreesC. The C (Ni,Pd)AI coatings show better cyclic oxidation resistance than simple aluminide coatings compared from the cyclic oxidation kinetics and the microstructure degradation of the two types of coatings. Palladium plays a significant role in alumina stabilization and in delaying the degradation of beta-phase

Effect of palladium incorporation on isothermal oxidation behavior of aluminide coatings

A (Ni, Pd)Al coating has been prepared by low-pressure pack cementation on the nickel-base superalloy IN738 with a preplating of Pd–20 wt.% Ni alloy. The coating consists mainly of a single phase of β-Pd(Ni)Al in the outer part and β-Ni(Pd)Al in the inner part. The oxidation behavior of the (Ni,Pd)Al coating at 900–1100°C was studied by TGA, XRD, and SEM/EDS. Results show that the transformation of θ- to α-Al2O3 is more rapid on the (Ni,Pd)Al coating than that on a simple NiAl coating. The addition of Pd to the aluminide coating facilitates the transformation of θ- to α-Al2O3e oxide scale formed and accelerates the diffusion of Ti from the substrate to the coating surface simultaneously.