NOVELTY - Making a rear electrode (10) structure for a photovoltaic device comprises depositing a conductive electrode comprising molybdenum (Mo) on glass substrate. The depositing step comprises sputtering at least one ceramic target comprising molybdenum oxide and at least one metallic target comprising Mo. The sputtering is performed in an atmosphere including an inert gas, and 0.1-10% nitrogen and/or hydrogen gas.    USE - Method of making a rear electrode structure for a photovoltaic device such as copper indium gallium selenide/copper indium selenide (CIGS/CIS) solar cell.    ADVANTAGE - The method provides a rear electrode having low stress, high conductivity, and good adhesion to the rear substrate.    DETAILED DESCRIPTION - Making a rear electrode (10) structure for a photovoltaic device comprises depositing a conductive electrode comprising molybdenum (Mo) on glass substrate. The depositing step comprises sputtering at least one ceramic target comprising MoOx and at least one metallic target comprising Mo. The sputtering is performed in an atmosphere including an inert gas, and 0.1-10 (preferably 0.1-3)% nitrogen and/or 0.1-10 (preferably 0.1-3)% hydrogen gas.    x= less than or equal to 0.1, preferably 0.03-0.10.    INDEPENDENT CLAIMS are included for:    (1) photovoltaic device comprising a front substrate (1); a front substantially transparent conductive electrode (3); an absorber semiconductor film (5); a conductive and reflective rear electrode; and a rear glass substrate (11) that supports at least the rear electrode, where the rear electrode comprises a first layer or layer portion comprising an oxide of Mo and a second conductive layer or layer portion comprising substantially metallic Mo provided on the rear glass substrate over at least the first layer, so that the first layer or layer portion comprising the oxide of Mo is located between the rear glass substrate and the second layer or layer portion comprising substantially metallic Mo; and    (2) method of making a photovoltaic device comprising using the electrode comprising Mo, supported by at least the glass substrate, as a rear electrode in a photovoltaic device.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross sectionals view of photovoltaic device.    Front substrate (1)    Front substantially transparent conductive electrode (3)    Absorber semiconductor film (5)    Light incident surface (5a)    Rear electrode (10)    Rear glass substrate (11)