Thin-film micro-concentrator solar cells

摘要： Concentrator PV (CPV) employs optical elements to concentrate sunlight onto small solar cells, offering the possibility of replacing expensive solar cells by more economic optical elements, and higher device power conversion efficiencies. While CPV has mainly been explored for highly-efficient single crystalline and multi-junction solar cells, the combination of thin-film solar cells with the concentration approach opens up new horizons in CPV. Typical fabrication of thin-film solar cells can be modified for efficient, high-throughput, and parallel production of organized arrays of micro solar cells. Their combination with micro lens arrays promises to deliver micro-concentrator solar modules with a similar form factor as present day flat panel PV. Such thin-film micro-concentrator PV modules would use significantly less semiconductor solar cell material (reducing the use of critical raw materials) and lead to a higher energy production (by means of concentrated sunlight), with the potential to lead to a lower levelized cost of electricity. This review article gives an overview of the present state-of-the-art in the fabrication of thin-film micro solar cells based on Cu(In,Ga)Se2 absorber materials and introduces optical concentration systems that can be combined to build the future thin-film micro-concentrator PV technology.