March 12, 2019 Source: Securities Daily

Open column: China's new energy industrialization has created countless achievements in the past 20 years, which are inseparable from innovation, especially from the contribution of China's new energy head enterprises. For example, it is technology that has supported the cost of photovoltaic modules and photovoltaics by more than 90% in the past decade, which has made China's PV industry chain products have an average global market share of more than 70%, and has been investing, scale, and market for many years. It ranks first in the world. In particular, the almost every technological leap and micro-innovation that occurs at the manufacturing end and the application side of photovoltaic products comes from the company's whimsy, independent research and development, and innovation.

From now on, "Securities Daily·New Energy" will search for innovative activities in China's new energy industry, and strive to find value for readers, promote innovation and development of the industry through our exploration, and enable China's new energy to establish its technology in the capital market. Image.

Affected by multiple factors, at the photovoltaic manufacturing end, the straight pull technology is getting hotter and hot, which has brought certain impact to the ingot casting technology.

However, under the strong advocacy of a group of ingot companies, a single-piece product based on ingot casting, called the "ingot single crystal" technology route re-active in front of the market, is considered organic to make ingot technology Regain the status. At the same time, the industry judges that the industrial foundation formed by the long-term accumulation of photovoltaic industry in China, which is formed around ingot technology equipment and industrial chain, will also provide strong support for the promotion of this technology route.

As early as the end of 2018, Yang Deren, an academician of the Chinese Academy of Sciences and director of the State Key Laboratory of Silicon Materials, once said that "the advantage of ingot single crystal is that the resistivity is more uniform, and the conversion efficiency is increased by more than 1% than polycrystal, while maintaining polycrystalline. The advantage of low light decay, light decay is only 20%-30% of the straight pull single crystal.

Recently, a voice believes that with the introduction of a batch of new products, ingots and single crystal products have gradually been accepted by the market through cost reduction and efficiency improvement. Especially since the end of 2018, ingot single crystals have been used in several major customer scale applications. Therefore, the era of ingot single crystal application has really come, and the market share will increase very quickly.

The market has not widely recognized the ingot single crystal

Yang Deren once positioned the ingot single crystal in a third technical route that is different from the ingot polycrystalline and Czochralski single crystal. In his view, "the ingot single crystal is grown by the ingot by the seed crystal." Monocrystalline silicon combines the advantages of both technologies with low cost, low power consumption, high quality and high efficiency."

However, in recent years, it has been a reality that the ingot single crystal technology was not finally applied on a large scale. Based on the opinions of all parties, the industry generally believes that this is due to the market share of ingot polycrystalline and Czochralski crystals.

Yang Deren once said that in the past few years, the industry has seen an increasing share of ingot polycrystalline, which is due to the rapid growth of investment in China's ingot polycrystalline enterprises. After 2015, the share of Czochralski crystals is increasing again, which is the result of a combination of policy market technology and economy.

On the whole, in recent years, “ingot casting single crystal technology has not been applied on a large scale. In addition to the rapid development of new technologies such as high-efficiency polycrystals, the cost problem has always been the main breakthrough direction.” Yang Deren believes.

Wan Yuepeng, chief technology officer of Poly GCL, has publicly stated that the previous generation of ingot single crystal products has not been widely promoted in the market because the components have crystal flowers and there is color difference; except for the appearance, the second is the tailing problem. These are the main bottlenecks affecting market-oriented applications.

Ingot single crystal has broken the bottleneck

As a proponent of the ingot single crystal route, GCL-Poly started the G1-Xin single crystal in 2011, and in 2013, developed the second-generation ingot single crystal product (G2-Xin single crystal), and then in 2017 A new generation of ingot single crystals (G3-Xin single crystal) was introduced.

In view of the appearance problems and tailing problems of the ingot single crystal mentioned above, Wan Yuepeng said that in the past few years, the main research work of GCL has been to increase the proportion of single crystal, reduce dislocations, and improve efficiency.

Summarizing the advantages of today's ingot single crystal products, Wan Yuepeng introduced that the appearance of Xin single crystal component products has completely eliminated the problem of crystal flower; the mass production efficiency of Xin single crystal PERC battery is compared with the straight pull single crystal on the same production line. The difference is less than 0.3% absolute efficiency; Xin single crystal PERC module has a power difference of less than 5Wp on the 72-piece full-range model and the Czochralski single crystal component; the ingot single crystal PERC battery and component have low light decay (LID, LeTID) The straight-drawn single crystal product of the same production line; the oxygen content of the ingot single crystal silicon wafer is less than 6ppma, which is significantly lower than that of the Czochralski single crystal; the resistivity of the ingot single crystal can be in a narrower range, which is beneficial to the PERC battery. Efficiency optimization; ingot monocrystalline silicon wafer batteries are more conducive to doping components than round chamfered cells; ingot single crystal products have a lower carbon footprint.

In addition, Wan Yuepeng also provided a set of data, three groups of customers who applied ingot monocrystalline products in batches, one of which was selected, the efficiency reached 21.8%, and more importantly, the tailing problem was on Xin single crystal G3. There is no more; another customer's battery performance is better, the efficiency reaches 21.95%; the third customer is different, is the black silicon velvet technology to do Xin single crystal, the efficiency reached 21.7%.