:The link you provide says nothing about thermoelectricity. It is a discussion of band diagrams and built in voltages which are unrelated to power-driving (voltmeter) voltages. An unfortunate aspect of solid state physics terminology is that the word "voltage" gets used in too many different ways. Electrostatic potentials, electron band energies, and Fermi levels can all be stated as voltages but it is only the Fermi level—the thermodynamic quantity—for which differences can supply real work. 
 :Here is an actual discussion of thermocouples from a university: http://www.me.umn.edu/courses/me4331/FILES/Thermocouples.ppt (I am sure there are many more, that is just the first hit I found when I googled for *thermocouple temperature gradient site:.edu*). Observe slide 5 where it is stated in words and equations that the emf occurs in temperature gradients. 
 :Regarding the electrochemistry of iron and zinc, that is just another type of emf unrelated to thermoelectricity. It also relies on the presence of an electrolyte, since aside from the small current, that iron and zinc masses are in equilibrium (0 volts difference) as they are shorted to each other; the disequilibrium occurs in the electrolyte and at the metal surfaces. Incidentally, electrochemical behaviour is also not related to built in voltages in the semiconductor sense; I don't think it's possible to calculate the 0.32 V iron-zinc cell open circuit voltage on the basis of band diagrams. 
 :(By the way, it's usually best if you add Talk page discussions at the bottom, for better chronological ordering.) 
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