Photoluminescence spectra of porous silicon modified by copper phthalocyanine coating
In this paper we present photoluminescence (PL) spectra of porous silicon (PSi) coated with thin top layer of copper phthalocyanine (CuPc). PSi was by electrochemical anodisation method prepared. CuPc based thin organic film was using physical vapor deposition (PVD) in high vacuum on the top of fresh PSi deposited. PL was under pulsed excitation measured and samples were in vacuum enclosed. PSi/CuPc samples exhibit strong photoluminescence in visible region at room temperature. Observed PL spectra exhibit multiband structure and such structure changes in red region compared to “clean” PSi. Properties of PSi/organic luminescence can be explained by penetration of organic material into PSi skeleton and interaction between carriers in PSi and deposited material.
PHOTOLUMINESCENCE, REFLECTIVITY AND RAMAN INVESTIGATIONS OF NANOCRYSTALLITES IN LUMINESCENT POROUS SILICON*
There has been a considerable interest in the physical properties of porous silicon prepared by anodization method [1-6]. In particular, porous silicon layers are attractive for the possible efficient light-emitting applications in the visible region. It opens the door for silicon as a possible material for optoelectronic applications. In the present time the basic requirement for the preparation of porous silicon layers is to obtain a good quality, stable layer on Si subStrate emitting efficient luminescence. In this paper the Raman scattering (RS), reflectivity (R), photoluminescence (PL) and photoluminescence excitation (PLE) measurements of the porous silicon layers prepared on (001) p/p+ silicon epitaxial wafers by anodization method are presented.
Numerical Simulation of Induction Heating Process of Continuous Casting Slab
Compared with traditional blazing furnace, the Continuous Casting-Direct Rolling is an advanced manufacturing steel technology, which can reduce energy waste, decrease pollution and enhance efficiency. The characteristics of steels during induction heating are complex, the change of material properties with temperature makes exact analysis methods very difficult to implement. Therefore, a powerful computer aided numerical tool (i.e., finite difference analysis) is selected to numerically model the induction heating process in this paper. The mathematic model coupling with electromagnetic field and thermal field was established, and it was solved by finite difference method (FDM), thus the slab temperature distribution and its variation with time were obtained, and the characteristics in whole induction heating process were studied. To validate the program feasible, the results were evaluated and compared with experiment results, which showed that the simulation results are reliable and effective. The skin effect in heating process from the two results was studied and demonstrated, the temperature change caused by different parameters such as the induced power intensity and the corner radian were also presented, which indicate that the slab temperature can be heated uniformly through adjusting these parameters, thus the continuous casting slab can meet the rolling requirement.