Chalcogenide solar cells of CZTS-Copper Zinc Tin Sulfide. A new, high-efficiency material for low-tech solar cells of earthabundant and environmentally friendly elements

Solar cells of CZTS (Copper Zinc Tin Sulfide) can revolutionize the world. There is

a global need for a drastic increase of energy production with low cost solar cells

of environmentally friendly materials. The aim of the project is to understand the

charge-carrier physics in thin films of the compound CZTS (Cu2ZnSnS4), to

characterize and produce films of this material and to develop a prototype cell

with a conversion efficiency of about 10 % - new world record - aiming at a

longer term efficiency of ~ 20 %. The current choice with high efficiency

approaching 20% is crystalline or polycrystalline silicon solar cells, which suffer

from an expensive, complex production process or CIGS [CuIn(orGa)Se2], which

unfortunately is limited by the decreasing availability and increasing cost of

indium. The efficiency of CZTS has recently reached 8.4 %. Nevertheless, the

physical properties of these thin film solar-cell materials including CIGS are not

yet understood. In the project the photo-physical properties of thin films of CZTS

will be systematically explored with the finite goal to produce high efficiency

materials. The objective is to achieve a break-through of the underlying physics

of CZTS for highly-efficient solar cells of this inexpensive, environmentally

friendly and abundant material. This can be done by a group with unique

expertise in complex chemical compounds from Solid-Oxide-Fuel-Cell (SOFC)

films, materials science, photo-physics, micro-, nanostructure-, terahertz physics

and solvation chemistry together with an innovative Danish company.