This report provides the outcomes of three ARENA projects to develop the next generation high efficiency solar cell, based on the three key technologies developed in these projects: laser doping, advanced hydrogenation, and simultaneous bifacial plating.
The first stage is to integrate the three technologies and fabricate laser doped and hydrogenated PERC and PERL cell devices with plated contacts.
One of the focuses is to implement the selective laser doped emitter technology on both the front and rear surfaces to create a bifacial PERL cell structure for optimum current generation and collection. Different lasers have been tested to develop suitable conditions for the selective laser doping process. Smooth laser doped lines with minimal laser-induced damage have been achieved after optimization.
Plating has been developed together with the laser doping process for metal deposition. To avoid using expensive silver and aluminium screen-print paste, low temperature metal deposition by light induced plating for laser doped bifacial PERL cell has been developed. The laser doping and self-aligned plating form closely placed narrow fingers with significantly reduced shading losses.
Smooth and uniform metal deposition on both the n-type surface and p-type surface has been achieved.
Advanced hydrogenation technology, which controls the charge state of hydrogen, has been integrated into the cell fabrication process. It improves the quality of commercial grade silicon wafers, eliminates LID and passivates laser induced defects introduced during the laser doping process.