From November 21 to 23, 2024, the 20th China Solar-Grade Silicon and Photovoltaic Power Generation Seminar (20th CSPV) was grandly held in Shenzhen. As an annual event that has attracted much attention in the photovoltaic industry, CSPV includes 2 theme forums, 20 special sub-forums, and hundreds of professional reports. It closely follows the cutting-edge technologies and latest applications of photovoltaics, jointly explores new technologies and development trends in the photovoltaic industry, releases research results, and shares technological innovation trends and future market trends. More than 1,000 representatives from photovoltaic companies, universities, research institutes, testing institutions, financial institutions and other experts and scholars attended the conference. Dr. Song Dengyuan, CTO of Yida Xinneng, Mr. Zhang Kangping, Director of the R&D Center, and Mr. Dai Jianfang, Director of Module R&D, were invited to attend and make special reports. Focusing on the N-type TOPCon platform technology, they released a number of the latest research results and provided a 28% efficiency improvement technology path and implementation plan.
In the main forum of the conference, Dr. Song Dengyuan delivered a keynote report entitled "Technical Route and Industrialization Progress of a New Energy High-efficiency Battery", which comprehensively and systematically expounded the panoramic technical route of a new energy "one main and three wings", and gave a technical path and implementation plan for improving efficiency by 28%. Dr. Song said that the mainstream technology of the photovoltaic industry mainly depends on three factors: industrial ecology, battery efficiency and cost per kilowatt-hour. Photovoltaics are essentially energy products that generate electricity. Photovoltaics must be economical as a clean energy to replace traditional fossil energy power generation, and the industrial ecology of photovoltaic technology determines the speed of cost reduction. The core competitiveness of China's photovoltaic industry is reflected in the complete industrial chain, and there is a good industrial environment that is self-controlled and controllable both horizontally and vertically, which provides a guarantee for photovoltaic products to achieve the best cost-effectiveness. In recent years, crystalline silicon technology has undergone several rounds of development and iteration, from P-type BSF and PERC technology to more efficient N-type technology. Among them, TOPCon best meets the above three elements of technical iteration and has high efficiency improvement potential. The product has become a new generation of mainstream technology with a market share of 70-80% of photovoltaic products with its advantages of high efficiency, high power, high bifaciality and low attenuation.
Dr. Song pointed out that the efficiency improvement potential of solar cells depends on its passivation structure. At present, crystalline silicon cells have shifted from local passivation to full-area passivation. TOPCon technology uses full-area SiO2/Poly-Si passivation contact technology, and its theoretical electron/hole carrier selectivity ratio can reach about 15, which is the best known passivation contact material. As a leader in N-type technology, Yidaxinneng has gone through deep cultivation and tempering, breakthroughs and innovations time and time again, and has the courage to climb on the road to the peak of efficiency. At present, the company's TOPCon technology has developed to 4.5 generations, and the fifth generation of products is ready to go. The average efficiency of the battery production line has reached 26.7%, and the open circuit voltage has reached 742mV, which continues to lead the innovative development of TOPCon technology in the industry. How will TOPCon technology improve efficiency in the future? Dr. Song gave a clear technical route, implementation plan and key technical parameters. We have simulated and calculated the efficiency improvement from the current 26% to 28%. The path is very clear and feasible. Through a series of means such as laser-assisted sintering technology, front and back Poly-finger technology, new metallization technology, tunnel barrier reconstruction technology, etc., we can achieve a conversion efficiency from the current 26% to 28%. I believe this efficiency will definitely be achieved.
"One main and three wings" go hand in hand
Dr. Song said that the "one main and three wings" panoramic technology route of Yida Xinneng's forward-looking layout has played the core platform advantage of N-type TOPCon technology, using TOPCon as the platform technology support, and developing multiple technology routes such as DBC, TSiP, and SFOS in parallel, all of which have achieved the expected innovative results. The DBC battery structure formed on the back with the TOPCon battery structure has been developed for three generations, and the path of the fourth generation technology has been given. The efficiency of the batch battery has reached 26.7%; TOPCon as the bottom battery of the stacked battery, combined with perovskite technology, etc., the perovskite/Si stacked battery (TSiP) currently has an efficiency of 33.2%; TOPCon as the bottom battery of the singlet exciton split layer will form an SFOS battery technology with an efficiency of more than 40%. It continues to improve on the road to pursuing the efficiency limit, escorting the optimal value of the product throughout the life cycle, and laying a solid foundation for the photovoltaic industry to create new quality productivity.
At the high-efficiency battery module technology sub-forum, Mr. Zhang Kangping delivered a keynote speech entitled "Prospects of BC batteries and the development of DBC technology". He said that DBC technology of Yida New Energy is a natural extension of the technical structure of the TOPCon platform. Relying on the tunneling layer technology of TOPCon 4.0 Plus batteries and integrating the selective contact full passivation solution, Yida New Energy's high-efficiency DBC products will be positioned in the distributed and BIPV market segments. The first generation of "Diamond Obsidian" DBC module products was released at the Shanghai SNEC exhibition this year. At present, DBC technology of Yida New Energy has developed to the 3.0 generation. DBC 3.0 battery technology adopts high-precision laser patterning technology and has a narrower electrode pattern design; the self-optimization anti-hot spot design of the battery cell can bring better module power generation performance; the all-black front light-trapping design highlights the excellent aesthetic appearance. DBC 3.0 batteries and modules of Yida New Energy have overcome a series of key technologies, and the battery efficiency has reached 26.7%. He finally elaborated on the new metallization technology solution of DBC 4.0, which provides new ideas for reducing costs and increasing efficiency of DBC technology.
At the 0BB Technology and Industrialization Forum, Mr. Dai Jianfang delivered a keynote speech entitled "Research on Different Busbar-free Interconnection Technologies and Reliability of Photovoltaic Modules". He said that Yidaxinneng released the first generation of 0BB TOPCon modules as early as August 2023. At present, Yidaxinneng's second-generation 0BB products have made new innovations and improvements in interconnection technology and reliability. He gave the reliability performance of Yidaxinneng's second-generation 0BB modules from the aspects of 0BB battery graphics design, interconnection scheme, and anti-hot spot technology. Through in-depth research on the mechanism, Yidaxinneng's 0BB modules passed the three-fold IEC 61215 international standard strict test, overcame the problem of 0BB module reliability, and achieved a maximum module efficiency of 24%. While improving the efficiency of the module, the silver consumption was significantly reduced by more than 10%, reducing optical shading to achieve better light absorption, thereby increasing power generation, and leading the industry to move towards low cost and high efficiency with technological innovation.
In the face of the ever-changing photovoltaic market, only continuous technological innovation is the driving force for the development of enterprises. Yidaxinneng relies on solid R&D genes and profound technical accumulation, takes N-type technology as the core, and takes the panoramic technology route as the starting point, and has been steadily moving forward on the road of technological innovation for many years. In the future, Yidaxinneng will continue to consolidate the core of technological innovation, forge high-quality photovoltaic products, actively create "photovoltaic +" full-scenario solutions, steadily expand the pace of internationalization, let every ray of sunshine bloom with value, and help Chinese photovoltaics become a more beautiful business card in the world!
