The calculation results of the surface plasmon（SP） energy and Purcell factor of ZnO/NiSi2 demonstrate the possibility of using NiSi2 to enhance the UV emission of ZnO by SP coupling.Experimentally,ZnO films were deposited on NiSi2 layers synthesized by ion implantation,and the roughness of the NiSi2 layers spans a large range from 3 to 38 nm,providing favorable conditions for investigating SP-mediated emission.An 11-fold emission enhancement from the ZnO film on the roughest NiSi2 layer was obtained,which indicates the possibility that metal silicide layers can be used both as an electrical contact and for emission enhancement.
A photoanode structure for dye-sensitized solar cells has been applied into the photocatalytic/electrochemical cooperative degradation of methylene blue solutions.The low eutectic point of titanium dioxide(TiO2)with a fluorine-doped tin dioxide(FTO)conductive layer results in a high reactivity of TiO2for the photocatalytic process as well as a good electron transfer for the electrochemical process.The porous TiO2layer maintains a large surface area for the degradations.Through the combinational process,the degradation velocity was improved by*36%,compared to a pure photocatalytic process.
Min YangXinling LiuJikun ChenFanqi MengYuliang ZhangHelmut BrandlThomas LippertNuofu Chen
Polycrystalline silicon(poly-Si) seed layers were fabricated on graphite substrates by magnetron sputtering. It was found that the substrate temperature in the process of magnetron sputtering had an important effect on the crystalline quality,and 700℃was the critical temperature in the formation of Si(220) preferred orientation. When the substrate temperature is higher than 700℃,the peak intensity of X-ray diffraction(XRD) from Si(220) increases distinctly with the increasing of substrate temperature.Moreover,the XRD measurements indicate that the structural property and crystalline quality of poly-Si seed layers are determined by the rapid thermal annealing (RTA) temperatures and time.Specifically,a higher annealing temperature and a longer annealing time could enhance the Si(220) preferred orientation of poly-Si seed layers.
Previous reports about the thermal conductivities of VO2 showed various temperature dependences across metal-insulator transition (MIT) temperature. In this work, polycrystalline VO2 samples were fabricated by spark plasma sintering of VO2 powder. Temperature dependences of their thermal conductivities were investigated using laser flash technique, and the thermal conductivity showed a significant decrease trend from metal-phase to insulator phase. Electrical transport properties were investigated to confirm both carrier and lattice contribution to the thermal conductivity. It is found that the lattice thermal conductivity decreased significantly across MIT point, which may be caused by soft phonon mode in metal phase of VO2 .
