Nanostructured solar cell materials for high efficiency photovoltaics: dream or reality?

摘要

Today's photovoltaic technology, based on mono or multicrystalline siiicon wafer is growing at a fast pace. Such a growth can be sustained by a second generation of solar cells, based on thin semi-conducting films of Si, II-VI or I-III-VI2. On a long term perspective, a third generation of photovoltaic devices is being prepared, that aims at a better use of the solar spectrum than what is currently achieved. This is something nanostructured materials might help to achieve. This paper presents the state of the art of wafer-based or thin film solar cells (inorganic materials) and the various concepts using inorganic nanomaterials for the elaboration of solar cells. More specifically, are described structures putting to use either quantum wells (to improve photon absorption and carrier collection) or quantum dots (as in new types of tandem cells, metallic intermediate band, multiple exciton or hot carrier solar cells) or nanomaterials that can also be used to adapt the incident solar spectrum before it is harvested by the solar cell. Experimental results, whenever available, are presented and discussed.