CIGS with Added Light Management
Renewable energy is one of the major challenges for our society. Solar cells are the most attractive long term renewable energy source, because of their low maintenance and high reliability. CIGS thin film panels are nearly competitive with crystalline silicon cells in terms of efficiency. However, in order to make it more competitive, the efficiency has to be increased and the cost has to be further reduced. The first point can be addressed by an antireflective coating (1) , the latter by CIGS layer thickness reduction (2) , which requires light management technology.
The goals of this project are to enhance the efficiency and the stepwise reduction of the CIGS absorber layer thickness and its associated costs, while maintaining a high efficiency.
The project is subdivided in five parts.
Design and manufacture light management technologies, which are actually front surface textures, that can capture the light at the air/front interface.
Replacement of native CIGS texture is needed when the layer thickness approaches 1.2 micron, because the feature size becomes too small to be effective. A smooth surface would lead to 2 mA/cm2 lower current density as compared to a rough surface.
Reduction of the CIGS layer to submicron levels without the loss of current density by introduction of a back reflector, as is commonly used in thin film Si.
A final step is the integration of back surface texturing with the TCO deposition in a single step.
Upscaling of the imprint technology to GEN 5 with the specific textures obtained from the previous steps.