Process simplifications to the Pegasus solar cell - SunPower´s high-efficiency bifacial silicon solar cell

We describe four simplifications made to the fabrication process of our high efficiency bifacial silicon solar cell, the Pegasus, and we examine the effect each of these has on cell performance. There is an increase in external series resistance in going to a single level metallization. There is an increase in short-circuit current by improving the back surface internal reflectance and improving the front surface texture. There is a small loss in efficiency when we increase the cell thickness. Incorporating these changes greatly simplifies the process by eliminating one-third of the major processing step and reduces the fabrication cost by 30%. All of this is done with only a 0.6% absolute decrease in the cell efficiency.