Better solar cells for harvesting the sun’s energy
Exploiting renewable forms of energy in a commercially relevant way has become a major goal in order to decrease dependence on our ever-decreasing supply of oil, providing economic and environmental benefits along the way. PV cells are used in calculators and watches, among other everyday devices. When approximately 40 PV cells are combined into modules and the modules are mounted on arrays, the solar panels frequently seen on rooftops and in PV parks across Europe can be used to power households or large utility or industrial sites. The ‘Roll-to-roll manufacturing technology for high efficient multi-junction thin film silicon flexible photovoltaic modules’ (SE-Powerfoil) project was designed to develop a new generation of highly efficient PV modules with longer operating lifetimes and reduced manufacturing costs compared to conventional methods. Specifically, the researchers developed flexible, thin-film silicon PV modules produced in a roll-to-roll process on metal foil. They used an innovative design procedure to produce and analyse individual cells rather than entire modules, achieving 11 % efficiency. In addition, they analysed the hot wire chemical vapour deposition (HWCVD) technique to deposit absorber layers on the solar cells and produce flexible PV modules, an economically viable alternative to rigid thin-film PV modules. Fast deposition technologies such as HWCVD were identified as critical for low-cost application and suitability for mass production. In addition, the researchers demonstrated increased efficiency and stability of the flexible modules with no effect on quality. In summary, the SE-Powerfoil project developed highly efficient, flexible thin-film silicon PV modules with enhanced durability and reduced manufacturing costs. The results should enhance European competitiveness in the PV market as well as enable more widespread use of PV cells.
