The Impact of Screen Printing on the Cost of Solar Cell Metallization

Photovoltaic generation of electric power requires substantial reduction of costs to tap significant markets. A major cost element in the technology of solar cell fabrication for space application is formation of electrical contacts by evaporation of metals through shadow masks. Application of conductive ink pastes by screen printing provides several mechanisms for cost reduction. Screen printing techniques have been developed for fabrication of miniature electronic circuits on ceramic substrates. The process is readily automatable, and equipment with high throughput rates is available. Thus, screen printing results in reduced investment, tooling and labor costs. Silver is required for the front metallization grid, and additional savings result from application of metal only where needed. Substitution of aluminum for silver at the back contact provides further material cost savings. Metallization costs by this method are projected to be less than .05 dollar (1975) per watt as compared to about 16.00 dollars per watt by evaporation techniques.