At a related seminar held recently, Oriental Risheng, a leading A-share photovoltaic company, delivered a keynote speech entitled "Latest Progress of Double-sided AlOx Passivation PERC Cells".
As the trend of photovoltaic parity access to the Internet becomes clearer, cost reduction and efficiency improvement have become the focus of the industry. In this context, PERC technology is favored for its multiple advantages such as high photoelectric conversion efficiency, low attenuation, and high power generation. According to the International Photovoltaic Technology Circuit (ITRPV2018) data, PERC cells will occupy a dominant market position. In terms of average mass production efficiency, the stable mass production efficiency of P-type crystalline silicon batteries has reached 21.6%. The agency predicts that by 2020, the efficiency of mass production of this technology is expected to exceed 22%.
International photovoltaic technology roadmap ITRPV forecast is mainly based on PECVD (Plasma Enhanced Chemical Vapor Deposition) technology based single-sided AlOx passivation technology, that is, AlOx only passivates the back of PERC cells. As a technology leader in the industry, Dongfang Risheng is "different", focusing on the industry's most promising, but the technical difficulty is relatively large. The double-sided AlOx passivation technology based on ALD (atomic layer deposition) technology, which uses AlOx Passivate the front and back of the PERC battery.
Dongfang Risheng is the first company in the world to achieve GW scale (~ 2GW) in mass production of double-sided AlOx passivated PERC batteries. In 2018, through a series of process optimizations such as selective emitter, oxidation, passivation, and metallization, the company finally achieved a substantial breakthrough in the production efficiency of double-sided AlOx passivated PERC cells. At present, the average efficiency of Dongfang Risheng double-sided AlOx passivated PERC battery has exceeded 22.19%, and the highest efficiency of the production line has reached 22.51%.
Dongfang Risheng's new PERC battery technology not only improves the battery efficiency, but also greatly reduces the light-induced attenuation of the battery, especially the light-induced attenuation (LETID) of PERC batteries under high temperature. Under the test conditions of 75 degrees Celsius, 1000W / m2, and 200 hours, the Oriental Risheng double-sided PERC battery showed excellent anti-light decay characteristics, and the attenuation rate was only ~ 1%. Compared with the industry's general test at 25 degrees Celsius, 1000W / m2, 5 hours, Oriental Risheng's internal testing methods are more stringent and scientific.
Seizing the opportunity of industry upgrading, Oriental Risheng frequently shot on half-sheet, PERC high-efficiency, white double-sided double-glass and other products, leading the industry. In October 2017, Dongfang Risheng's first batch of high-efficiency half-chip modules was applied to the Shanxi Yangquan photovoltaic leader project. In October 2018, Orient Risheng's first batch of 72 high-efficiency 72-piece 370W white double-sided double-glass modules was used in the Baicheng Frontrunner Base. In the future, Oriental Risheng will further improve the efficiency of PERC batteries, strengthen research and development in metallization, slurry, and new passivation structures. In combination with module-side innovation, it is expected that 400W double-sided modules will be put into production in 2019.