Passivated Edge Technology – Introduction
Solar modules comprising cut cells are meanwhile part of the standard portfolio of almost every solar module manufacturer and supplier, with an increasing trend towards half cut/multi cut cells and shingle technology. The shingle technology l uses solar cells not only being cut in half but also into multiple strips (3, 4 to 8). By dividing the cells, the electrical resistance of the metallization decreases, leading to a higher efficiency of the solar modules in comparison to the use of full cells, e.g., M10, G12. This even overcompensates Voc losses caused by damaged etches after cutting processes.
A further significant boost in module performance can be achieved by the Passivated Edge Technology (PET). This technology involves the deposition of a passivation layer on the cut edges which enhances the overall performance of the cut cell and finally increases the efficiency gain of the module even further. While for half-cell modules the utilization of PET can already achieve an efficiency boost of several percent, this effect becomes even more significant for reduced cut formats used for shingle modules. SINGULUS TECHNOLOGIES offers the new vacuum deposition system GENERIS PET, an industrialized solution for PET that is particularly characterized by high throughputs at low cost.
GENERIS PET Concept
After cell cutting, typically performed by a laser-based process, the half cells or cell stripes are bundled into stacks. The stack transfer and loading on the carrier tray of GENERIS PET is fully automated. A unique, in-house developed carrier tray design facilitates processing of several thousand cell parts (stripes) per tray due to the high packing density that can be achieved. In addition, it enables the deposition of the passivation layers to be restricted to the cut edges, thus preventing undesired wraparound of the passivation to the cell surfaces.
The GENERIS PET represents an industrialized inline solution for PET that can achieve half-cell throughputs of several GW per year, depending on the equipment configuration and readily suitable for any crystalline solar cell technology. The universal GENERIS PET design allows for processing of all current and future wafer and cut formats. In addition, its stand-alone design features facile integration into existing solar cell and module manufacturing lines and fabs as well as utilization as a stand-alone tool along with the laser cutting tool.
In summary, the excellent passivation layer properties achieved by the GENERIS PET serve towards high efficiency gains of up to 1% on a multiple cut and shingle cell level compared to its unpassivated counterpart.