a good place to start is the book by Mark E. Ozarem and Bernard Tribollet "Electrochemical Impedance Spectroscopy (Wiley 2008), apart from some textbook, like P.W.Atkins "Physical Chemistry" (Oxford University Press 1986).
Specifically to your question. This is really hard to answer because for the time being , the electron transfer processes across metal electrode-sample interfaces are very poorly understood from the microscopic point of view. Faradaic process (Faradaic current across the interface) - I believe it is modelled by what is known as "charge transfer resistance" - is a phenomenological description of the redox reaction, which is, to my knowledge, almost never properly connected to the rest of the system - electrolyte or whatever is to the right of the electrode.
Just to help you on the way, the Faradaic current is usually the "bottleneck" of the electrical response (smallest current measured, when you are approaching dc measurement). This means that the charge transfer resistance is the highest resistance of the system and better the electron transfer across the interface, the lower will be this resistance. This might be taken as a measure of the "Faradaic efficiency". As I see it, when the electron transfer across the interface is "perfect" (the current through the system determined first of all by the bulk of the sample itself ), this resistance will "disappear".
At present, I work on this problem and I might have something more later in 2017, if you will be interested.
Thank you for the answer. I really appreciate your explanations. Many publications mention faradaic efficiency and IPCE statistics but did not exactly mention how they calculate it. I see what you meant.
Also, I am really interested and currently looking in EIS application to study the electron diffusion length in water oxidation processes.
Is there a paper you would recommend to read in relation to the problem you are currently working on? I want to read your 2017 publication.
1. As soon as the paper will be published, I will put it on the Research Gate if at all possible. In case there will be some problems, please let me have your e-mail address and I will send it to you.
2. Electron diffusion length in water oxidation processes - very interesting problem, but I have no knowledge of any good reference at this point.
I am happy that my comments seem to have helped you on the way.