New and enhanced silicon thin-film solar cells (NEST)

General Information: NEST is a project uniting five European research groups, having a long collaboration history, in the common task of developing silicon thin film cell technology well off present efficiency, stability and technological barriers. The research organizations that participate in this project have achieved up to now stable efficiencies around 10%, holding the European record in a-Si cells, and stable efficiencies of 7.7% on completely μc-Si normal p-i-n cells. The main goal of the project is to develop in the next two years, inverted stacked tandem cells, by incorporating the promising μc-Si bottom cell and by applying major innovations and new technical solutions to the existing know-how of tandem solar cells. Namely the new tandem structures that will be developed are inverted tandems grown on metal and plastic substrates, that will contain the new completely stable microcrystalline silicon bottom cell. Significant effort will be dedicated to the development of new top TCO layers for the inverted structure, that will have superior behaviour in the conditions imposed by the incorporation of the new layers, improved buffer layers, tunnel junction, and light trapping techniques.
A major part of this study is devoted to the optimization and deposition rate enhancement of the microcrystalline layers, and further improvement of its optical absorption.
The tools used for the achievement of these tasks in a non-empirical manner, include extensive process, interface, materials and device function analysis. As a result, it is expected to achieve completely stable tandem eff1ciencies in excess of 10% and will to module efficiencies better than 9%.

Start Date: 1997-06-01

End Date: 1999-05-31

Duration: 24 months

Project Status: Completed