Precursor ink for producing IB-IIIA-VIA semiconductors

A method for making a semiconductor film with the general formula Cu(InaGabAlc)SeyS2-y, where 0.7<a+b+c<1.3 and 0≦y≦2, by the following steps:

• a) Selenium, sulfur or both are dissolved in a liquid organic solvent. The chemical composition of this liquid organic solvent includes one or more of the elements phosphorus, sulfur and oxygen.
• b) The liquid organic solvent produced in step a) is mixed with a plurality of particulates of metal sources or metal compounds selected from IB, IIB and IIIA.
• c) Formulation a precursor ink by mixing a) and b) and a functional solution for adjusting viscosity, increasing ink stability and containing sodium ion to promoting CIGS crystal growth.
• d) Apply the precursor ink c) on substrate and followed with a baking process under elevated temperature at vacuum.
• e) Chalcogenize the baked film of d) at atmosphere of chalcogen vapor and/or at atmosphere of hydrogen chalcogenide to cause some of the components of the ink produced in step c) and deposited on a substrate in step d) to react and creating the desired polycrystalline semiconductor film.