Fujifilm files patent for flexible solar cell technology

Fujifilm used to be a major competitor when I was involved in photographic film and plate manufacture for Kodak.  It is interesting to see that they have converted their expertise in these areas to the fabrication of flexible Aluminium based films for solar cell technology.  In a recent announcement Fujifilm Corp announced they have formed a CIGS photovoltaic (PV) cell on an aluminum flexible substrate and achieved a conversion efficiency of 17.6% with an aperture area of 0.486cm2.  Also, they confirmed a conversion efficiency of 12.5% with an aperture area of 72cm2.

Interestingly a US patent application (US20100224249) appeared just a few days ago covering this technology.  Fujifilm used anodic oxidation to form an aluminium oxide (Al2O3) layer on an aluminium foil as the substrate which is treated with a diffusion barrier layer of either titanium or chromium. On the substrate, a molybdenum (Mo) layer, CIGS layer, cadmium sulfide (CdS) layer and zinc oxide (ZnO) layer are stacked. Furthermore, sodium doping is used to increase conversion efficiency.  Full details can be found in their concrete examples 1 and 2.  A comparison with an example not containing the diffusion barrier layer had a lower conversion efficiency.