European Union allocates 10 million Euros to thin film solar cell project
Zinc oxide nano-rods as anti-reflective coating on a CIGSe solar cell.
©HZB
European research consortium's German partners to include Berlin's Helmholtz Centre and Free University
In the context of its 7th annual 'Framework Programme for Research and Technological Development,' the European Union has approved funding in excess of 10 million Euros for the thin film solar cell project "Scalenano" through 2015. Thirteen different European research groups will collaborate on co-developing chalcogenide solar cell technology with the common goal of cutting production costs while using nanostructured materials to increase thin film module efficiency. The consortium will include Germany's Helmholtz Centre Berlin (HZB) and the Free University of Berlin.
To date, copper indium gallium diselenide (CIGSe) has proved the most efficient of the chalcogenide materials. Traditionally, a process known as vacuum coating has been used to deposit several layers of CIGSe a few micrometers thick onto a glass or foil surface. In an effort to cut costs, one of this European collaborative's many goals includes development of new, environmentally-friendly production methods that are vacuum-independent.
Using new material and building element concepts including use of nanostructured materials, the goal is to bring about a breakthrough increase in efficiency. Through the electrochemical synthesis of nanocrystalline precursors and using new techniques for printing nano particles - similar to the way ink is used in printing - the researchers hope to tap new methods of production. To ensure its success beyond the laboratory setting (which normally uses only a few, isolated solar cells), the scientists aim to test production concepts for purposes of a potential upscale.
Headed by Dr. Thomas Unold, the HZB team's main focus will be on quality control and process monitoring. Development of innovative analytical tools for solar cell characterization during production is already under way. The scientists are hopeful that they will ultimately be able to use these tools to improve the quality of the chalcogenide absorptive material while ensuring high yield and high performance during the upscale.
The new research strategy will also combine thin film absorptive materials with nanostructured transparent conductive oxides (TCOs). In this area of research, the team led jointly by Professor Martha Lux-Steiner and Dr. Sophie Gledhill of the Free University of Berlin and HZB, respectively, are working on adapting, optimizing, and optically modeling zinc oxide nanoarray coated chalcogenide solar cells.
The Berlin-based researchers are also hard at work on the next-generation chalcogenide thin film materials known as kesterides - materials with properties similar to CIGSe albeit minus the indium component, an element, which occurs only rarely in the Earth's crust.
- Shedding light on insulators: how light pulses unfreeze electronsMetal oxides are abundant in nature and central to technologies such as photocatalysis and photovoltaics. Yet, many suffer from poor electrical conduction, caused by strong repulsion between electrons in neighboring metal atoms. Researchers at HZB and partner institutions have shown that light pulses can temporarily weaken these repulsive forces, lowering the energy required for electrons mobility, inducing a metal-like behavior. This discovery offers a new way to manipulate material properties with light, with high potential to more efficient light-based devices.
- Lithium-sulphur batteries with lean electrolyte: problem areas clarifiedUsing a non-destructive method, a team at HZB investigated practical lithium-sulphur pouch cells with lean electrolyte for the first time. With operando neutron tomography, they could visualise in real-time how the liquid electrolyte distributes and wets the electrodes across multilayers during charging and discharging. These findings offer valuable insights into the cell failure mechanisms and are helpful to design compact Li-S batteries with a high energy density in formats relevant to industrial applications.
- Self assembling monolayer can improve lead-free perovskite solar cells tooTin perovskite solar cells are not only non-toxic, but also potentially more stable than lead-containing perovskite solar cells. However, they are also significantly less efficient. Now, an international team has succeeded in reducing losses in the lower contact layer of tin perovskite solar cells: The scienstists identified chemical compounds that self-assemble into a molecular layer that fits very well with the lattice structure of tin perovskites. On this monolayer, tin perovskite with excellent optoelectronic quality can be grown, which increases the performance of the solar cell.