Patent ID: 8969720
Filing Date: 2015-03-03
Classification: C23C,H01L,Y02E,Y02P

Abstract:
1. A method of making a chalcogen-containing photoabsorbing structure, comprising the steps of: (a) forming a first film precursor capable of being converted into a first PACB film, the first film precursor comprising at least Cu, In, optionally at least one of Ga and Al, and at least one chalcogen, wherein at least a portion of said forming of the first film precursor occurs at a temperature of less than about 350° C. and wherein the first film precursor as deposited includes at least 50% of the stoichiometric amount of the at least one chalcogen relative to the Cu, In, optional Ga, and optional Al; and (b) forming a second PACB film directly or indirectly on the first film precursor or the first PACB film, wherein the second PACB film is photoactive and comprises at least Cu and In and a chalcogen, and wherein a major portion of the second PACB film has a crystal grain size greater than 300 nm; and (c) subjecting at least the first film precursor and optionally a precursor of the second PACB film to an annealing and/or chalcogenization treatment under conditions effective to convert the first film precursor into the first PACB film, wherein a major portion of the first PACB film comprises crystalline grains having a size in the range from about 5 nm to about 100 nm such that the first PACB film has a finer grain structure than the second PACB film.