How much thickness you want for silver electrodes?

You can deposited silver on crystal using thermal evaporator or E-beam.

I want to do I-V of crystal then I need contacts.

Deposit 100 nm Ag thin film using mask for I-V measurement.

You can also make 2 point contacts using Ag paste .

Hi,

Probably the best is to deposit a thin-film of silver, as comented before, but if it is for connection you can use silver epoxy resin, or adhesive copper, or even a conductive ink pen (not sure, but you can check "circuit scribe").

Good luck!