The present project aims to develop intermediate-band solar cells based on quantum dots. The intermediate-band device is among the candidates for a third generation solar cell technology, having an upper limit for the efficiency that is twice that of curr ent devices used for terrestrial electricity production. Third generation solar cells used either as flat panels or in concentrator systems will potentially make solar electricity a major (i.e. cost competitive) contributor in global electricity productio n in this century. The overall goal is to establish, through experimental work, a fundamental understanding of how the efficiency of intermediate band solar cells can be optimized. This demands control over fabrication processes for the individual mater ials and for the resulting solar cells. Moreover, beside the development of intermediate band solar cells, the project also forms a basis for other proposed designs for high efficiency solar cells, such as hot carrier cells and up/down conversion of photo ns. Both of these alternative routes to high efficiencies are proposed realised using nanoparticles or quantum dots. The project will establish a firm foundation for future innovation in existing and coming Norwegian Solar cell industries.