Design
The CIS solar cell consists of the following functional layers:
- Carrier material
A metal foil, preferably stainless steel, is used as the carrier material. Other foils made of copper, titanium or molybdenum have also been tested and are theoretically possible carrier foils. - Back contact
The layer has the function of forming as low a contact resistance between the supporting material and the absorber as possible. Molybdenum is used for this. - Absorber
The absorber layer consists of copper (Cu), indium (In) and selenium (Se). It can be doped with gallium (Ga). In total, this layer is two thousandth of a millimetre thick. It has the task of converting the penetrating light into electrical energy (direct current). - Buffer
The buffer layer consists of a metal sulphide. - Front contact
The front contact or the window layer together with the buffer completes the solar cell. It consists of transparent zinc oxide and has the task of conducting the solar electricity to the contacts (grid). - Grid
The grid consists of fine contact wires that collect the solar electricity.