The intent of project Demo 14 was the development of groundbreaking concepts including new and innovative materials as well as device concepts in order to increase efficiencies of silicon thin-film solar cells. The project's objective was the production of solar cells with stable efficiencies over 14% as a basis for the development of cost efficient solar modules with stable cell efficiencies of more then 13% ready for production in industrial scales. The project has been headed by Masdar PV, a manufacturer of solar cells, and performed together with Forschungszentrum Jülich, PVcomB and ZIB. The demonstration of the process on 30 x 30 cm^2 solar modules with efficiencies greater than 13% was a milestone of the project. In addition, a specialized computer program was developed tailored to optimize the optical properties of thin-film solar cells based on the actual three dimensional geometric properties of the solar cell including all the randomly textured layers.