Increase The Absorptive Capacity Of Light Of The Photocells By Embedded In Bow-tie Antenna

With the deterioration of the Earth's natural environment and human awareness of environmental protection, solar, wind, geothermal, biomass and other new kinds of energy are payed more and more attention, they are green and easy to use, without pollution, oil, coal and other traditional fossil energy sources will soon dry up, there are wide space for the research and use of these new kind of energy.The silicon photocells is a new kind of green energy sources by useing solar energy, it is a kind of semiconductor devices that can transform the solar energy into electrical energy, its basic structure is a PIN knot. The silicon between the two electrodes are mainly consist of monocrystalline silicon and polycrystalline silicon, when the sunlight stimulate on the silicon photocells, the photoelectric effect will generate inside of the silicon, it will form a lot of electron-hole pairs, they will make directional movement to the two electrodes by the influence of the electrodes. Some of them reach the electrodes, this is the working principle of silicon photocells.At first crystalline silicon is applied to make silicon photovoltaic, crystalline silicon is an indirect band gap semiconductors, its absorptive capacity of light is weak, in order to increase the efficiency of the photocells, the thickness of this kind of photocells has to reach about 200um～300 um; In order to reduce the cost of crystalline silicon photocells, people uses a thickness of 5um～10um of polycrystalline silicon photocells. It can be very difficult to guarantee the efficiency as people reduces the costs at the same time. Additional, in case of the large number of defects in polysilicon, the reaching probability of the electron-hole pairs will be much lower. In order to improve light absorption efficiency, people use the polysilicon thin films with rough surface, however, it will bring more defects. Therefore, the key point to solve these problems is how to increase the efficiency as far as to compress the thickness the photocell.It was suggested that the surface plasma wave can be used to resolve this problem by its field enhancement effect, surface plasma research is a hot topic today, when metal surface exposed in specific frequency of light, free electrons in the metal surface cause collective coherent shocks, electromagnetic wave will be formed between the metal and dielectric's surface. It has spatial locality, local field enhancement and other features, it is widely used in the field of antenna technology, bio-technology and so on. Some scholars doped nanometer-scale metal particles in the polysilicon films, it formed surface plasma waves on the surface of these metal particles, around the metal particles there forms local field enhancement effect, it enhances the ability of generating electron-hole pairs, this can guarantee the absorptive capacity when people compress the thickness of the crystals。In this paper, the method is embedding bow-tie antenna into a polycrystalline silicon thin-film, simulate the electric field distribution when the sunlight irratiate throughout the silicon film, estimate the number of electron-hole pairs generated, and by the contrast, try to prove that with the same efficiency,the model embedded in bow-tie antenna can be effectively compressed the film thickness.