CuInSe2 and related materials for thin film solar cells

CuInSe2 and related compound proved to be very efficient materials for thin film solar cells. Efficiencies exceeding 16 % have been achieved in several laboratories. The material system Cu(In,Ga)(S,Se)(2) provides the possibilities for the optimization in view of photovoltaic application regarding energy gap and electronic properties as well as fabrication of structures with graded gap. Basic properties of the material which have to be taken into account for film deposition and the photovoltaic properties of heterojunction are presented. An overview about the different developments in this field and the status of solar cell efficiencies and prospects of future developments will be given.