This report provides an update on the development and commercialisation of novel device structures and technologies for achieving high efficiency commercial silicon solar cells at a competitive cost.
The focus of the ARENA 2014/RND068 project was the development and commercialisation of novel device structures and technologies for achieving high efficiency commercial silicon solar cells at a competitive cost. Achieving higher cell efficiency usually requires sophisticated processes, some of which carry considerable costs incapable for transfer to mass production. The priority for this project, however, was to develop technologies focused on increased simplicity and the ability to exploit lower- cost materials. This included the use of low-quality commercial-grade silicon wafers instead of those produced using the highest purity of silicon. Although these materials may contain crystallographic defects, cost effective methods can be used to improve the quality of silicon to be comparable to more expensive wafer technologies.
Four key aspects of solar cell design and production processes were developed during this project:
- Eliminating the need for expensive microelectronics grade processing such as photolithography and pattern dielectric layers, by instead using laser processes to achieve the patterning;
- New processes, such as laser processing, were developed and optimised to pattern the rear dielectric layer to form localised rear contacts on the solar cell;
- Implementation of the new advanced hydrogenation technology into the solar cell design and fabrication to lower cost by transforming low cost, low quality silicon wafers into ones which are comparable in quality to expensive high-quality wafers.
- Replacement of expensive silver metal contacts with low cost copper plated contacts.
Solar modules fabricated using this technology have achieved IEC certification.
A production “blueprint” (commercialisation package) for the manufacture of these next generation solar cells using the new technologies has been developed to help ensure a smooth transfer of the technology to industry.