California, United States [RenewableEnergyWorld.com] Applied Materials Inc. has introduced its Baccini Esatto Technology, a high precision, multi-step screen printing capability for Applied’s Baccini back-end solar cell processing systems. Featuring proprietary hardware and software innovations, the Esatto Technology is designed to increase the efficiency of crystalline silicon (c-Si) solar cells by enabling the fabrication of advanced contact structures.
The first of several applications of the Esatto Technology is for double-printed metal line deposition where it has been shown to raise absolute cell efficiency by as much as 0.5%. The result of several proprietary hardware and software innovations including high resolution imaging, screen alignment, and advanced process control, the Esatto Technology allows multiple layers of different materials to be overlaid with better than ±15μm repeatability.
Applied’s Esatto Technology was designed to enable advanced contact formation techniques such as double-printed frontside metal lines and the multiple process flows required to create selective emitter structures. In a production environment, Esatto Technology allowed the replacement of single 120μm wide lines with two-layer, double-height lines less than 80μm wide on the finished cell.
In a related story, DuPont and Applied Materials announced a collaboration to advance multiple printing technology that is expected to increase the absolute efficiency of crystalline silicon (c-Si) photovoltaic (PV) solar cells by more than 0.5 percent, according to company estimates.
“We’re working with innovative suppliers like DuPont to integrate highly customized material formulations with our leading-edge solar manufacturing systems to drive down the cost per watt of solar energy,” said Charles Gay, president of Applied Solar at Applied Materials. “By using our Baccini back end systems equipped with Esatto Technology™ and DuPont Solamet photovoltaic metallization paste, customers can achieve the precision alignment, repeatability and process control that enables successful multiple printing.”
Photovoltaic metallization pastes are screen printed onto the surface of solar cells in a pattern of grid lines which serve to collect electricity produced by the cell and transport it out. To maximize efficiency in the solar cell, the multiple printing technology will reduce the shadowing effect of wide grid lines on solar cells and improve electrical conductivity.
Applied Baccini Esatto Technology together with DuPont Solamet photovoltaic metallization pastes enables narrower and taller grid lines to be precisely printed in two or more layers. In addition to demanding precise alignment of the patterning system, multiple printing requires the paste to be finely tuned to perform consistently during all printing passes.