I was reading that for high frequency switching applications with semiconductors, the ratio of the electron to hole mobility should be high.

Why is it so? Is it a necessary condition always? Or just one of many possible ones?

As per my basic understanding, for high switching applications, taking the simplest case of a diode, the reverse recovery time should be dependent on the time the minority carriers in each side of the junction take to return to the opposite side on application of a reverse bias from a forward-biased state. Now, a scenario like that would ideally want both the mobility of electrons and holes to be high.

What I inferred from this condition is also that this necessitates that the difference between the electron mobility and the hole mobility should be high enough for the ratio to be appreciable.

Any insight on this would be helpful.

  • \$\begingroup\$ A hint could be, that electrons are faster than holes. \$\endgroup\$ – stowoda Oct 30 '18 at 5:28
  • \$\begingroup\$ Yes, I'm aware of that. Mobility of electrons is higher than that of holes. Yet, why should we be concerned with the ratio of their mobilities? \$\endgroup\$ – Curiosity Oct 30 '18 at 5:37
  • \$\begingroup\$ Maybe to prevent fast recombination so electrons are available for conduction. \$\endgroup\$ – stowoda Oct 30 '18 at 5:44
  • \$\begingroup\$ Well, fast recombination is needed in high switching applications, I believe. Its about switching, not conduction. \$\endgroup\$ – Curiosity Oct 30 '18 at 5:53
  • \$\begingroup\$ Sounds reasonable. Now I am curious, too. \$\endgroup\$ – stowoda Oct 30 '18 at 6:03

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