Preparation of copper-indium-gallium-diselenide precursor films by electrodeposition for fabricating high efficiency solar cells

A process for preparing a photovoltaic device gallium-containing precursor film, the process comprising the steps of:

• providing a substrate;
• providing an electrodeposition bath containing ionic copper, indium, and selenium, and gallium in the approximate relative ratios of 1, 5, 1.5, and 5, respectively;
• inserting said substrate into said electrodeposition bath;
• and
• forming a thin film layer by simultaneously electrodepositing copper, indium, selenium and gallium from said electrodeposition bath onto said substrate.

A process for preparing a photovoltaic device gallium-containing precursor film, the process comprising the steps of:

• providing a substrate;
• providing an electrodeposition bath comprising approximately 0.01-0.02M copper ions, 0.05-0.15M indium ions, 0.05-0.15M gallium ions, and 0.01-0.03M selenium ions
• inserting said substrate into said electrodeposition bath;
• forming a metal-containing film by simultaneously electrodepositing at least three elements from said electrodeposition bath onto said substrate;
• and
• depositing by physical vapor deposition additional material selected from the group consisting of copper, indium, gallium, and selenium, onto said metal-containing film to achieve a final stoichiometry for said metal-containing film and said additional material, combined, of approximately Cu.sub.1 (In.sub.1-x Ga.sub.x)Se2 wherein x is within the range of approximately 0.34 to 0.50.