NOVELTY - Electrodeposition solution comprises: a solvent; a group IB material source that dissolves in the solvent and provides a group IB material; a group VIA material source that dissolves in the solvent and provides a group VIA material; at least one complexing that forms a complex ion of the group IB material where the complex ion dissolves in the solvent; an adhesion promoting agent; and a corrosion inhibitor, where the pH of the electrodeposition solution is 1-13.    USE - The electrodeposition solution is useful for electrodepositing group IB to group VIA thin films (claimed). The electrodeposition solutions are useful: to manufacture solar cell absorber layers; for forming copper-selenium films, which are used in the preparation of group IB, IIIA, VIA compound semiconductors; and for the preparation of precursor layers in a two-stage process on conductor layers.    ADVANTAGE - The electrodeposition solutions: provide uniform, smooth, continuous and compositionally repeatable Group IB-Group VIA alloy or mixture films; suppresses or eliminate the formation of selenium particles in the electrodeposition solution, thus allowing electrodeposition of defect-free and highly adherent, low stress Group IB-Group VIA alloy or mixture thin films at a high deposition rate in both conformal and non-conformal fashions; provide excellent adhesion which results in a large increase in the cathodic efficiency for plated films; suppress or eliminate the dissolution or partial dissolution of some substrate thin film material during the electrodeposition step, and has enhanced substrate wetting and coating uniformity due to the addition of glycerol; and are capable of electrodepositing a very high selenium content film.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a method of electrodepositing an adherent film comprising copper selenide alloy material on a conductive layer, comprising: providing an electrodeposition solution comprising a solvent, a copper ion source, a selenium ion source, at least one complexing agent and at least one adhesion promoting agent, the adhesion promoting agent suppressing the formation of colloidal particles on the substrate and in the plating solution, where the electrodeposition solution has a pH value in the range of 1-13; contacting the electrodeposition solution with the surface of the conductive layer and an anode; establishing a potential difference between the anode and the conductive layer; and electrodepositing the copper selenide film on the surface of the conductive layer; and    (2) a method of electrodepositing a precursor on a conductive layer, comprising: electrodepositing a copper selenide film on the conductive layer using an electrodeposition solution, the electrodeposition solution comprising a copper ion source, a selenium ion source, at least one complexing agent, at least one adhesion promoting agent; depositing a thin film including a group IB material, at least one group IIIA material onto the copper selenide film, where the step of depositing uses a physical vapor deposition technique.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a precursor stack electrodeposited on a base.    Precursor stack (100)    Base (101)    First layer (102)    Second layer (104)    Optional third layer (106)