Thin film solar modules based on CIS prepared by the co-evaporation method

CuInSe₂ (CIS) and related compounds have demonstrated their high potential for high efficiency thin film solar cells. A key issue for the development of modules is upscaling of the CIS absorber deposition. Different preparation methods have been applied. For transferring all process steps on large area with high throughput and process yield, the strategy is to optimize the methods available in view of highest device performance. For the deposition of the different films, standard techniques for optimized small area devices have been applied. For the upscaling of CIS deposition, a quasi in-line system for 10 cm×10 cm substrates was constructed. In a second step, a real in-line system for 30 cm×30 cm substrates with linear evaporation sources was developed. This system is already in operation and uniform Cu(In,Ga)Se₂ (CIGS) films have already been produced. Based on laboratory processes, static and dynamic, about 50 modules with an aperture area up to 90 cm² and 10 to 15 interconnected cells have been prepared. For the 30 cm×30 cm technique, all film depositions from the gas phase are based on in-line processes. Mo and ZnO films are sputtered from linear magnetron targets and CIS is deposited by co-evaporation onto moving substrates. All process steps including patterning, electrical contacts and encapsulation have been set up and films with sufficient quality and uniformity for 30 cm×30 cm solar cell modules have been produced