TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The step of adjusting the pH of the solution comprises adding a base to the solution to adjust the pH of the solution from 2 to 3. The method of preparing the selenium electroplating solution further comprises adding at least one metal salt to the solution, where the metal salt is at least one of copper salt, zinc salt, indium salt, gallium salt or tin salt; adding at least one organic additive to the solution, where the organic additive has at least one nitrogen atom or at least one sulfur atom and the organic additive is thiourea, thiazine or benzene sulfonic acid; adding at least one metalloid halide to the solution, where the metalloid halide comprises bismuth chloride; and adding at least one chloride ion source to the solution, where the chloride ion source comprises at least one potassium chloride or sodium chloride. The electroplating method further comprises annealing the film at 100-300 degrees C for 30-60 minutes. The method of fabricating the photovoltaic device further comprises annealing the absorber layer. The step of forming the buffer layer comprises: preparing a second selenium electroplating solution comprising (a)-(c) as above per se, zinc salt and base, where the pH of the solution is 2-3; and electroplating the buffer layer on the absorber layer using the second solution as the plating bath. Preferred Components: The selenium oxide comprises selenium dioxide. The substrate comprises glass, metal or plastic substrate. The buffer layer comprises zinc-selenium. The metal salt comprises: a copper salt or an indium salt, and the absorber layer comprises a copper indium selenide absorber layer; copper salt, indium salt or gallium salt, and the absorber layer comprises a copper indium gallium selenide absorber layer; and copper salt, zinc salt or tin salt, and the absorber layer comprises a copper zinc tin sulfide absorber layer.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The base comprises sodium hydroxide. The acid comprises methanesulfonic acid. EXAMPLE - No suitable example given.