No abstract

No abstract

N-type ZnO/SiOx/n-type crystalline silicon isotype heterojunctions (HJs) have been prepared by magnetron sputtering. Native and thermal oxides were employed as the interlayer between the Si substrate and the ZnO film. Transmission electron microscopy and x-ray photoelectron spectroscopy revealed that an oxide layer was inserted in the HJ interface, with thickness of ∼1.2 nm (native oxide) and ∼2.0 nm (thermal oxide). Atomic force microscopy and x-ray diffraction spectroscopy showed that the ZnO film on the Si substrate consists of tightly packed grains with sizes in the range 50–150 nm and is c-axis preferred orientation. The electrical properties were characterized by current–voltage (I–V), capacitance–voltage (C–V) and current–voltage–temperature (I–V–T) measurements. By a comparison of the HJ properties, the n-ZnO/thermal oxide/n-Si HJs show improved electrical properties, with a fairly low leakage current and high rectification ratio, although the series resistance increased. Studies of fitting the I–V–T measurement data suggest that the tunnelling process is a dominant current transport mechanism for the n-ZnO/native or thermal oxide/n-Si HJs at an intermediate voltage range.

No abstract

The various Co 2 MnSi films, from chemical ordered L2 1 state to completely disordered amorphous state, were prepared on glass substrates with different deposition/annealing temperatures. The influence of deposition/annealing temperature on the crystallographic defects and atomic disorders, and further on the magnetic and transport properties of the Co 2 MnSi films were investigated in detail. The decrease in crystallinity leads to the structure disorder, spin disorder and further the reduction of magnetization as well as the increase of residual resistivity. The dominant source in anomalous Hall effect for the polycrystalline samples is the skew scattering, while the skew scattering coefficient a becomes larger with the increasing deposition temperature, due to the increase of skew scattering center introduced by the increasing structure disorder.