Review of Ni-Cu Based Front Side Metallization for c-Si Solar Cells

الملخص EN

Given the high percentage of metal cost in cell processing and concerns due to increasing Ag prices, alternative metallization schemes are being considered.

Ni-Cu based front side metallization offers potential advantages of finer grid lines, lower series resistance, and reduced costs.

A brief overview of various front side patterning techniques is presented.

Subsequently, working principle of various plating techniques is discussed.

For electroless plated Ni seed layer, fill factor values nearing 80% and efficiencies close to 17.5% have been demonstrated, while for Light Induced Plating deposited layers, an efficiency of 19.2% has been reported.

Various methods for qualifying adhesion and long term stability of metal stack are discussed.

Adhesion strengths in the range of 1–2.7 N/mm have been obtained for Ni-Cu contacts tabbed with conventional soldering process.

Given the significance of metallization properties, different methods for characterization are outlined.

The problem of background plating for Ni-Cu based metallization along with the various methods for characterization is summarized.

An economic evaluation of front side metallization indicates process cost saving of more than 50% with Ni-Cu-Sn based layers.

Recent successful commercialization and demonstration of Ni-Cu based metallization on industrial scale indicate a potential major role of Ni-Cu based contacts in near future.