National 863 project energy field photovoltaic industry major issues "efficiency of more than 20% based on efficient back-end and back passivation technology of crystalline silicon battery industry complete sets of key technology and demonstration production line", in May 2014, the project's battery production process Technology to obtain a major breakthrough, the use of alumina passivation process PERC battery single photoelectric conversion efficiency of 20.5%, batch average efficiency of 20.35% or more, alumina passivation process has been completed mass production process debugging.
According to the staff of the research group, the conversion efficiency of the battery is internal test, and the calibration standard is the standard of Fraunhofer ISE, the German Fraunhofer Institute. PERC efficient battery, the back of the passivation process was originally used for the thermal oxidation process, pre-has a very good conversion efficiency of 20.44%, now has the thermal oxidation passivation process of mass production conditions. The use of PERC battery on the back of the passivation layer of alumina, relative to the thermal oxidation method, alumina technology, a low-temperature process, the process is less than 300 ℃, for the low-temperature process. This process can be applied to promote the polycrystalline PERC battery, the latter can achieve the efficiency of polycrystalline battery continues to improve for all crystalline silicon wafer as the substrate of solar cells, has a wide range of applications, the alumina process Debugging success, for its application provides the technical conditions.
PERC efficient battery with a new battery structure design, the use of ordinary solar grade silicon, in the ordinary battery production line, based on the addition of only two or three kinds of equipment to complete the production, can be based on the original production line to upgrade and transformation, that is, PERC can achieve high-quality battery production, complete low-cost and efficient solar crystal silicon cells and existing production line seamless docking, in order to achieve low-cost crystalline silicon battery production line upgrade.
"More than 20% of the efficiency of crystalline silicon solar cell sets of major technology and core equipment technology, built with independent intellectual property rights of high-performance crystalline silicon solar cell demonstration production line, and the formation of bulk products," plans to the end of 2014 will be more than 20% efficiency of the battery Mass production, reduce power generation costs, improve the cost of photovoltaic power generation and conventional thermal power competitiveness. This is firmly grasp the future high point of the status of the energy industry in the domestic and international markets to form the core competitiveness and promote the rapid and healthy development of new energy has a very important significance.