Recently, certified by the Institute for Solar Energy Research (ISFH) , an authoritative testing institution in Germany, Maxwell has achieved a photoelectric conversion efficiency of 25.94% on full size (M6, 274.4cm2) monocrystalline HJT cell via using low-indium transparent conductive oxides (TCO) technology combined with copper plating busbars of SunDrive.
In April of this year, Maxwell achieved a photoelectric conversion efficiency of 25.62% on HJT cells of the same type, which was also certified by ISFH, using low-indium TCO technology combined with silver-coated copper paste. In only four months, the R&D team of Maxwell has realized the ideal combination of the special low-indium TCO and copper plating technology with its highly-efficient innovation. On that basis, SunDrive optimized the direct plating technology without seed layer, improving the aspect ratio of the electrode (the width and height of busbars reached 9 μm and 7 μm respectively). With joint efforts, Maxwell and SunDrive increased the conversion efficiency of the low-cost HJT cells to 25.94%.
(Figure) Data from the certification report of ISFH
The high cost of HJT cells was mainly caused by the indium in ITO target material and silver in low-temperature silver paste. The certified cells developed by Maxwell and SunDrive adopt the magnetron sputtering for TCO film coating. Compared with common HJT cells (without low-indium solution), they adopt the low-indium solution of Maxwell and thereby reduce the use of indium in single piece by 50%. Another 40% reduction can be reached as the indium decrease solution of equipment is added, which reduces the amount of indium to 30% of the normal level; In addition, the copper plating technology eliminates the high cost of silver paste. Therefore, the combination of these two technologies will minimize the manufacturing costs of HJT cells while ensuring the outstanding photovoltaic conversion efficiency.
To promote the mass production of HJT cells and enhance the application of HJT technology, Maxwell not only concentrates on the development of equipment for the whole production line of HJT cells, but constantly extends the R&D and optimizes various aspects in terms of material, mass production and manufacturing costs, which aims to meet the demand of cell and module manufacturers . With all the efforts, the Company strives to provide high efficiency and low-cost integrated solutions for manufacturing of HJT cells. Maxwell has made the new breakthrough in efficiency of low-indium and silver-free HJT cells, denoting its steady progress to propel the "cost reduction and efficiency improvement" of the photovoltaic industry.