The usual wisdom about Schottky diodes is that their \$V_f\$ is around 0.2 to 0.3 volts, but what specifically determines this?
I know that for p-n diodes, doping concentration can affect the forward voltage. Is this also true for Schottky diodes? Obviously at some point you have a non-rectifying ohmic junction, but you have a range of possible dopant concentrations below that point.
What would happen if you made a Schottky diode with germanium instead of silicon? Germanium p-n diodes have a much lower forward voltage than silicon p-n diodes, so would a germanium Schottky diode have a lower forward voltage than a silicon Schottky diode? What about a SiC Schottky diode, would it be higher?
Does the choice of metal for the metal-semiconductor junction matter? Is the forward voltage related to the metal's work function at all?