Hi, I have a problem with copper electrodes. I spin-coat TPD on them and due to differences in work function of the copper(4.7eV) and TPD(5.4eV) I do not get almost any current from such a system. You can take a look at TPD here http://www.sigmaaldrich.com/Area_of_Interest/Europe_Home/Germany.html just type in the CAS number 65181-78-4. It is also worth mentioning that TPD is a photoconductor. Similar system just with gold electrodes worked quite good (work function for gold 5.1eV). My question is what can I do to shift the Fermi energy level upwards. There must some kind of a compound that deposited on top of silver shifts its energy levels. At least I hope it exists)) Thanks for all the help.