How 'thin' are we talking about? Assuming you CdS film is in nanometer/micron range, you might not want to make a contact by Pb soldering (if this is what you mentioned above. Not only your film might get damaged, but it will be hard to define the exact electrode size which you'll need to calculate the conductivity)
Depending on what your film is, you can make the contact by sputtering or metal evaporation (e.g: e-beam metal evaporation).
Hi, thanks for your support: I was thinking in the range of 50-100nm for CdS and in the range of 500nm to 700nm in the case of Al:ZnO. What do you propose in those cases?