An electrochemical deposition method and electrolyte to plate uniform, defect free and smooth gallium films are provided. In a preferred embodiment, the electrolyte may include a solvent that comprises water and at least one monohydroxyl alcohol, a gallium salt, and an acid to control the solution pH and conductivity. The method electrodeposits a gallium film possessing sub-micron thickness on a conductive surface. Such gallium layers are used in fabrication of semiconductor and electronic devices such as thin film solar cells.