TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The copper species comprises a copper ion including cupric ion and/or cuprous ion. The window layer is cadmium sulfide, zinc sulfide, zinc selenide, zinc oxide or zinc magnesium oxide. In method (I): the copper indium disulfide material comprises a thickness of copper sulfide material, where the thickness of copper sulfide material is selectively removed using a solution of potassium cyanide (310); the copper indium disulfide comprises a p-type semiconductor characteristic; and the window layer comprises an n+-type semiconductor characteristic. In method (II), the copper indium disulfide material after compensation has a p-type semiconductor characteristic.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Method: The method (I) and (II) further comprises introducing an indium species in the window layer to cause formation of an n+-type semiconductor characteristic. The method (II) further comprises: subjecting at least the copper poor copper indium disulfide material to a thermal treatment process at 100-500?Oc; and forming a transparent conductive oxide overlying a portion of the window layer. The step of subjecting the copper species or the step of compensating is provided by at least one process including spin coating, spraying, spray pyrolysis, pyrolysis, dipping, deposition, sputtering or electrolysis. The thermal treatment process is provided in an environment containing at least a sulfur bearing species comprising hydrogen sulfide in a fluid phase. In method (I): the step of subjecting at least the multi-layered structure to a thermal treatment process is performed at 100-500?Oc; the step of forming the copper layer and the indium layer are provided by a sputtering process or plating process; the copper species compensates for any missing copper in the copper poor surface; and the copper indium disulfide material is mixed with a copper indium aluminum disulfide or copper indium gallium disulfide. EXAMPLE - No suitable example given.