SBIR Phase I: Novel buffer layers for superior superconductor films on a low-cost substrate

This Small Business Innovation Research Phase I project aims to increase the commercial use of high temperature superconductors (HTSs) by reducing component costs and increasing manufacturability. Specifically, the innovation is to produce high-quality HTS thin films on a new substrate material that is a fraction of the cost of substrates currently in commercial use. The incompatibility in the physical properties of the proposed low cost substrate and HTS material prevent commercial application at present. This incompatibility will be bridged by an innovative buffer layer grown between the substrate and HTS. The research objectives are focused on identifying the critical parameters of the buffer layer that result in superior HTS films suitable for practical applications. A series of HTS thin films with different buffer layer variations will be grown. The films will be characterized by atomic force microscopy. In addition, their transition temperature and critical current density will be measured. A prototype commercially-relevant HTS film with optimized buffer layer parameters, fabricated on a low-cost substrate, will be the end product of the Phase I research. The broader impact/commercial potential of this project is that it enables a high-performance superconductor wireless filter product that can be produced at greatly reduced costs over comparable superconductor filters. The filter will reduce dropped calls and increase base station range, thus enhancing the customer's wireless experience. Wireless carriers will benefit from reduced infrastructure costs due to a lower number of base station installations, which will also have a beneficial environmental impact. The immediate target markets of the innovation are cellular base station original equipment manufacturers (OEMs), and wireless operators. The total market for wireless filter equipment is $400 million per year and is growing at 22% per year. The project will also result in an increased understanding of the role of buffer layer designs on thin film properties, which will have a benefit in other areas, such as magnetic thin films and other thin film material systems where incompatible substrates limit commercial applications.