A Cost-Effective Alternative to Dispensing Ag Ink for Highly Efficient Si Solar Cell Contacts

Cost-effective production of the solar cell, a semiconductor device which converts sunlight directly to electricity without any polluting by-products, will lead to widespread affordability of solar electricity. The solar cell uses silver (Ag) for its front contact, which is the second most expensive layer of the device. In order to decrease the cost, less Ag should be used, which can be achieved through inkjet printing as opposed to screen-printing technology, currently most common in the solar cell industry. Inkjet printing technology is appealing since it can produce finer gridlines, use less Ag, produce uniform gridlines (from cell to cell and on the same cell), and lower contact resistance on lowly doped emitters. In this work, the inkjet gridlines were fabricated in two ways: (i) inkjet seed/plate (IJSP) and (ii) inkjet seed/full-grid (IJSF). The IJSF contact is fabricated similarly to the screen-printed (SP) counterpart, while the IJSP contact requires the use of Ag plating solution to plate after high temperature contact firing. Through the electroluminescence (EL) measuring technique and the Suns-V
OC
measurements, similar performance metrics for the IJSF and SP contacts were obtained, while the IJSP contact had the weakest performance. With a total of 1.31% less overall metal coverage than the SP contact, the IJSF contact used less Ag while achieving the same performance.