Hi,

I wanted to model an heterostructure device with the thermionic emmision model at the interface. I'm familiar with the thermionic current density equation which is more or less:

J~A* *T^2 * exp(Phi_B/Vt) * [exp(Va/Vt)-1].

But then I came accros a paper that explains that it is equivalent to write the current across the heterojunction interface by means of the electron densities as follow:

J~q(n1*v1-theta*n2*v2*exp(-phiB/Vt))

*"Numerical Modeling of Heterojunctions Including the Thermionic Emission Mechanism at the Heterojunction Interface".

Is there a good source for the derivation of the two equations and how they are related (or some simple intuitive explanations), are they realy equivalent or am I missing somwthing?

Moreover, in the second term there is no external voltage dependancy (the [exp(Va/Vt)-1] term).

Thanks