Possibilities of new materials for solar photovoltaic cells

Abstract The requirements for desirable technological properties of semiconductors for photovoltaic conversion are discussed and two criteria are suggested for the selection of materials that could guide the search towards low melting compounds made of cheap component elements: (1) the use of a deviation from ideality vs. energy gap diagram for the prediction of energy gaps from the knowledge of melting temperatures or viceversa; (2) the use of the Parthe-Goryunova-Mooser-Pearson criteria for compounds of which only their chemical formula is known but not their structure, in order to guess the structure and therefore be able to use the first criterion. For materials for Schottky devices a third criterion is necessary, derived by Nethercott that relates the Mulliken electronegativities of the component elements of a compound to its electron affinity. This can also be applied in the search of metallic alloys, semimetals or narrow band gap semiconductors that might replace the metal in a Schottky barrier. It is shown that a number of compounds exists which might meet these criteria.