I-Corps: Reactive Inks for Next Generation Metallization of Solar Cells

Arizona State University, Scottsdale AZ

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project can widely affect the implementation of photovoltaics, by significantly reducing the cost without compromising on device performance. The low temperature silver reactive inks are projected to use 90 percent less silver than traditional screen-printing technologies. Additionally the low temperature process will use significantly less energy and utilize equipment with relatively low capital expenditures requirements and high throughputs. This technique is of particular importance to temperature sensitive devices and substrates, not only because the reactive inks do not require firing but also because low temperature screen printing silver paste are costly, even more so than their high temperature counterparts. Thus the path envisioned for this technology not only can radically change the cost structure of solar cells but it also has the potential of affecting other markets such as wearable electronics, flexible displays and building integrated devices. This I-Corps project further develops findings in the field of evaporation-confined adhesion promotion and reactive ink chemistry. It is based on application of reactive inks to photovoltaics, optimization of adhesion pretreatments, and understanding of printing and drying kinetics of the multiple chemical solutions involved in the process. It has been demonstrated that the process can reduce silver consumption by an order of magnitude and obtain comparable high efficiency to a screen-printed heterojuntion device. It has been further demonstrated that the reactive silver metallization is compatible with the state-of-the-art smart wiring technology for module assembly, reducing the silver consumption even further. It has also been shown that the reactive ink printed modules can withstand damp heat accelerated testing without any signs of performance loses, corrosion or delamination of the modules.