2. Polycrystalline chalcogenide systems

In the polycrystalline sector, two options have clearly stood out in recent years for their performance and ease of implementation: the CdTe sector and the CuInSe ₂ sector (and its Cu(In,Ga)Se ₂ variant, also known as CIGS), both of which are most often combined with a CdS window layer.

As we shall see, the performance of polycrystalline materials is closely linked to grain size and orientation. The type of conduction is generally governed by the chemical composition, in particular the deviation from stoichiometry, which means that layer doping is often unnecessary.