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?

  • \$\begingroup\$ Very good +1 question .The SiC has more bandgap so it will waste more foward volts . \$\endgroup\$ – Autistic Dec 2 '18 at 3:38
  • \$\begingroup\$ That was my guess, yeah. But how much higher? \$\endgroup\$ – Hearth Dec 2 '18 at 3:42
  • \$\begingroup\$ A highly simplified discussion exists here. There's a whole lot more to it (what happens when you use several metals in an amalgam; semiconductor atoms will migrate into the metal even at room temps; differences vs annealing process; differences vs cleaning procedures; ohmic vs schottky due to fermi level relationships; to mention just a few things at mind immediately.) But at least it is a start. \$\endgroup\$ – jonk Dec 2 '18 at 4:54

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