How Can dI/dV Help Determine Fermi Level and Band Gap in Semiconductors?

[KayDee01]

I'm supposed to be working with an STM in the coming weeks to determining the Fermi Level of some semiconductor diamond films.

I was bombarded with a lot of information by my lab supervisor and the bit of my notes about the calculation just says "Differential of voltage vs current allows us to directly observe the band gap and fermi level". I know how to use the equipment to collect information about varying voltage and tunnelling current information, but I'm a little lost as how I should be calculating the fermi level and band gap once I have all the data.

Any ideas?

 

[ZapperZ]

Look up what dI/dV tells you. Hint: it has something to do with the tunneling density of states.

Zz.