I have a plot log (I) = f(U) for a few diodes: Silicon diode, Germanium diode, some LED and a Zener diode. I need to determine the material, from which the Zener diode is made based on the positioning of its characteristics. What parameter should I look for to determine it? I thought about checking the band gap somehow, but I am not sure whether it can be determined by just having a plot log(I) = f(U).

And if I know the difference between voltages (for specified current) of two diodes , let's call them A and B, and I have some information about diode A (including its band gap), can I calculate the band gap of the B diode?

  • \$\begingroup\$ The material is Silicon not silicone \$\endgroup\$ Nov 18 '13 at 16:30

I'm not sure if I understand your problem, but if you want to determine which of the four types of diodes you have you can look at the forward voltage (V_f) and reverse voltage when diode starts to conduct at reverse polarity (V_r) and maybe reverse leakage current (I_rl) before that point:

  • Si-Diode: V_f ca. 0.6 V, large V_r, low Irl
  • Ge-Diode: V_f ca. 0.3V, relative large I_rl
  • LED: relative large V_f (> 1V, e.g. 1.4 V, depending on material)
  • Si-Zener-Diode: V_f ca. 0.6V, V_r = V_zener
  • \$\begingroup\$ Would Germanium Zener Diode have V_f ca. 0.3 V or have I misunderstood your answer? \$\endgroup\$
    – 3yakuya
    Nov 20 '13 at 0:16
  • \$\begingroup\$ @Byakuya: Yes, I guess a Ge Zener-diode would have V_f ca. 0.3V. I have, however, never ever met a Ge-Zener diode (or a Zener diode made of anything else but Si). \$\endgroup\$
    – Curd
    Nov 29 '13 at 10:18

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.