Towards cheap efficient silicon solar cells: architectures and atoms

Timely replacement of fossil fuels by renewables depends on further steep falls in generation costs leading to widespread 'grid parity'. In the case of solar energy, reduction in the cost of photovoltaic solar cells is a crucial factor. First generation solar cells, which currently dominate the market, have simple architectures including front side contacts, are cheap and easy to produce, but are too inefficient to support truly low-cost solar energy.
Second generation cells such as SunPower's interdigitated back-contact (IBC) cells are expensive, harder to produce, and owing to their smaller market niche benefit less from economies of scale. Third generation cells - both efficient and cheap to manufacture - are urgently needed.

This talk describes a novel approach and device geometry that promises both high efficiency and low cost. Initial experimental results validate the concept, and computational modelling using the Sentaurus TCAD suite shows that a low-cost device with an efficiency approaching 24% (comparable to current high-cost IBC cells) is achievable. Part of the benefit from the proposed technology comes from increased efficiency due to the device structure, and part from its lower manufacturing cost and improved tolerance for the use of poorer quality solar-grade wafers.

The talk will conclude with a short description of atomistic modelling work at Newcastle aimed at improving our understanding of defects in solar-cell materials.