Sulfur is used to improve the performance of CIGS devices prepared by the evaporation of a single source ZIS type compound to form a buffer layer on the CIGS. The sulfur may be evaporated, or contained in the ZIS type material, or both. Vacuum evaporation apparatus of many types useful in the practice of the invention are known in the art. Other methods of delivery, such as sputtering, or application of a thiourea solution, may be substituted for evaporation.
GOVERNMENT SPONSORED RESEARCH
This invention was made with government support under NREL Subcontract No. ZAK-8-17619-21, Prime Contract No. DE-AC36-99GO10337 awarded by the Department of Energy. The government has certain rights in this invention.