Current techniques for the production of CIGS thin films do not leverage stationary small area, high rate, production technologies that allow for the precise control of thin film properties. Development and production of CIGS, and many other thin films, have focused on the use of large area substrates or continuous moving roll-to-roll deposition methods.
While CIGS holds the record for best thin film cell performance at nearly 20% in smaller area devices, scaling these laboratory results to large area devices has proved costly and difficult, resulting in significantly lower product efficiencies. With proven laboratory results, we believe we can use small area substrates to provide improved solar cell performance by statistically reducing process variation and defects to the solar cell that have occurred when manufacturing processes have been scaled to large areas in efforts to produce commercial quantities.
Interestingly, a number of manufacturers of CIGS today use large area or continuously moving roll-to- roll substrates in an effort to mass produce and then cut these large areas up into smaller wafer sized pieces for use in solar module assemblies. They sacrifice quality for quantity and the net results are products that deliver only fractions of the CIGS potential.
While starting and finishing with small area substrates may seem counter intuitive to the manufacturing economies-of-scale sought by developers of large area manufacturing systems, XsunX believes that the capability to directly transfer laboratory results and processes, or to improve and optimize processes in smaller areas, will allow commercial scale production to achieve or maintain improvements to the physical properties and efficiencies of the CIGS cell. US National Renewable Energy Laboratories routinely achieves 17% average efficiencies for CIGS with 19.9% peaks using a 4-inch substrate. Common sense dictates that if you already have a process in place that is delivering high efficiency results you should focus on developing a way to put the process to work making millions of high performance solar cells per year per system.
Our revolutionary manufacturing method combines the higher cell efficiencies achieved through small area processing techniques with the high rate processing techniques developed within the hard disc media industry. We believe that through the successful combination of these techniques, overall factory yields (total watts of production per day) will be increased thereby resulting in lower production costs while still delivering the full energy and low cost potential that CIGS based devices can offer.