NOVELTY - A thin film solar cell is fabricated by forming a barrier layer (200) overlying the surface region to maintain the sodium within the soda lime glass substrate (100); forming a first molybdenum layer using a first process where the first molybdenum layer has a first thickness and being in tensile configuration overlying the barrier layer; and forming a second molybdenum layer using a second process where the second molybdenum layer has a second thickness which is greater than the first thickness, and being in compressive configuration overlying the first molybdenum layer.    USE - Method of fabricating a thin film solar cell (claimed).    ADVANTAGE - The method fabricates film that is easy to mechanically integrate with each other, having good reliability, and can be used for extensive periods of time in conventional environmental applications.    DETAILED DESCRIPTION - A thin film solar cell is fabricated by:    (A) providing a soda lime glass substrate (100) comprising a surface region and a concentration of sodium oxide of greater than 10 wt.%;    (B) treating the surface region with cleaning process(es) using a deionized water rinse to remove surface contaminants having a particles size of greater than 3 mu m;    (C) forming a barrier layer (200) overlying the surface region to maintain the sodium within the soda lime glass substrate;    (D) forming a first molybdenum layer using a first process where the first molybdenum layer has a first thickness and being in tensile configuration overlying the barrier layer;    (E) forming a second molybdenum layer using a second process where the second molybdenum layer has a second thickness which is greater than the first thickness, and being in compressive configuration overlying the first molybdenum layer;    (F) patterning the first molybdenum layer and the second molybdenum layer to form a lower electrode layer (300);    (G) forming a layer of photovoltaic material overlying the lower electrode layer; and    (H) forming a first zinc oxide layer overlying the layer of photovoltaic materials.    An INDEPENDENT CLAIM is included for a thin film solar cell comprising:    (1) a soda lime glass substrate comprising a surface region and a concentration of sodium oxide of greater than 10 wt.%;    (2) a barrier layer overlying the surface region, and maintaining the sodium within the soda lime glass substrate;    (3) a lower electrode layer comprising a first molybdenum layer overlying the barrier layer and a second molybdenum layer overlying the first molybdenum layer, the first;    (4) an absorber material comprising a copper, an indium, a gallium, and a selenium species overlying the lower electrode layer; and    (5) a first zinc oxide layer overlying the absorber material.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic view of a method of fabricating a thin film solar cell.    Soda lime glass substrate (100)    Barrier layer (200)    Lower electrode layer (300)    Absorber layer (405)    Window layer (408)