NOVELTY - A glass substrate (1) bearing electrode(s) (preferably molybdenum-based) in the form of a thin layer (100 thick) comprises a barrier covering (2) (80-500, preferably 100-150 nm thick) comprising layer(s) of mixed oxide of zinc and other element(s) (4 wt.%) containing at least 10% zinc arranged between the substrate and the electrode (3).    USE - Glass substrate for electronic device, particularly photovoltaic solar cell (claimed).    ADVANTAGE - The glass substrate has a thin layer of electrode that forms an effective barrier to greatly reduce the migration of alkaline ions coming from the substrate when this is heated, and has a very favorable effect on conductivity of the electrode after thermal treatment.    DETAILED DESCRIPTION - A glass substrate (1) bearing electrode(s) (preferably molybdenum-based) in the form of a thin layer (100 thick) comprises a barrier covering (80-500, preferably 100-150 nm thick) comprising layer(s) of mixed oxide of zinc and other element(s) (4 wt.%) containing at least 10% zinc arranged between the substrate and the electrode. The thin layer of electrode (3) is subdivided into greater than or equal to 2 layers formed by cathodic sputtering under different deposition conditions. A layer of selenide and/or sulfide of copper and indium or of copper, zinc and tin is deposited on the electrode. The electrode, after undergoing a thermal treatment at 500 degrees C for 30 minutes and protected from oxidation, has an electrical resistance of less than 0.8, preferably less than or equal to 0.6 ohms, and did not detach from the substrate when subjected to an adhesion test. The barrier covering (2) comprises a stack of greater than or equal to 2 layers of different compositions (preferably zinc-tin mixed oxide of different compositions, particularly tin ( greater than or equal to 20, preferably 40%) and zinc (40%)).    DESCRIPTION OF DRAWING(S) - The drawing is a cross-section of a glass sheet bearing an electrode.    Glass substrate (1)    Barrier covering (2)    Electrode (3)