The latest advances in solar cell technology based on crystalline Silicon are being driven by a desire to reduce the thickness of the Silicon wafer, primarily due to the cost of Silicon. This has forced the development of new designs in three key areas; moving the front-side contact to the back to eliminate its masking effect, replacing the screen printing process used to define metal contacts, and developing methods to localize the regions of high doping to facilitate contact formation.
Laser-Fired Contacts (LFC) is technology whereby contacts are formed using metals deposited on a solar cell with an insulating layer between the metal in the Silicon. A laser pulse drives the metal through the insulator and into the Silicon, locally alloying with the Silicon and forming a low-resistance ohmic contact. Using our flexible PyroFlex™ laser platform, ESI has been able to explore and characterize the many different mechanisms at play during this process, and home in on a pulse configuration which consistently produces low-resistance contacts.
Laser Fired Contacts (LFC)
- Aluminium on Silicon
- Sub-Ohm contact resistance
- Shaped pulses 100’s of ns.
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