Solar power economic development in the 21st century as the most decisive influence on five technical areas of new energy and renewable energy in one, because of its environmentally friendly, efficient, energy-saving and inexhaustible, with no exhaust and other characteristics, has become the most watched new energy energy. Therefore, efforts to strengthen the solar photovoltaic industry and other research and development, and constantly improve the photoelectric conversion efficiency of an enterprise in the future to win the fierce competition in the market, and constantly promote the photovoltaic industry and technological progress and more large-scale application of the critical crystalline silicon solar cells the mainstream of current photovoltaic industry in order to improve the competitiveness of enterprises in the market, improve the conversion efficiency of crystalline silicon solar cells is imminent.
Conventional silicon solar cells require the trapping of light in the surface texture of the use of chemical suede, increases the surface area, this light reflection through / absorption reduces reflectivity. However, the presence of suede and also had a negative impact, the position of suede furrow poor contact with the metal produces the phenomenon. Therefore, we consider the back surface of the wafer is polished, the wafer back surface is more smooth and even the mirror effect, back flat on the back of the wafer after polishing, one can enhance the reflectance of transmitted light transmittance decreases, on the other hand can make contact with the wafer surface aluminum paste and more fully to improve the passivation effect.
By polishing the back surface, respectively, the current density Jsc and the open circuit voltage Uoc been improved, which can improve the conversion efficiency of the solar cell, this is by means of this test was verified.
A solar cell
The basic structure of the crystalline silicon solar cell shown in Figure 1, the base material is a p-type crystalline silicon, the thickness of about 200μm; upper surface of the layer of n +-type diffusion region, and the substrate photovoltaic effect constitute the basic structure - pn Results;
Uniformly cover the entire upper surface of the passivation film with an anti-reflection; top surface area of the front grid-shaped electrode, the back surface by screen printing, and then sintered to form an aluminum back surface field layer is covered with BSF (BackSurfaceField) and the back electrode, a positive electrode and contact with the n + region, BSF and the back electrode to form an ohmic contact with the p-type region, the production process shown in Figure 1.A.
- 2013/09/27(金) 11:50:14|