Chalcogenide-based solar cells are receiving attention because of their low manufacturing costs and demonstrated ~20% efficiency in laboratory-scale small-area devices. Theoretically, these devices should be capable of 30.5% efficiency, according to the Shockley–Queisser limit and, thus, surpass DOE’s SunShot goals for cost-competitive solar power.
To date, however, CIGS modules have not surpassed 15 % efficiency, and incremental engineering has been slow to close the gap with the Shockley–Queisser limit. It is believed that 7% (abs.) efficiency is lost due electrostatic potential variations at charged extended defects like grain boundaries and dislocations.