Then infinite recombination velocity on the contacts is assumed.
The left hand side of the device is given a reference potential of 0 V. See figure 4. We can then write the energy of the LUMO and HOMO on the left hand side of the device as:
![]() |
(1) |
![]() |
(2) |
For the left hand side of the device, we can use Maxwell-Boltzmann statistics to calculate the equilibrium Fermi-level (
).
![]() |
(3) |
We can then calculate the minority carrier concentration on the left hand side using
![]() |
(4) |
The Fermi-level must be flat across the entire device because it is in equilibrium. However we know there is a built in potential, we can therefore write the potential of the conduction and valance band on the right hand side of the device in terms of
to take account of the built in potential.
![]() |
(6) |
we can now calculate the potential using
![]() |
(7) |
The minority concentration on the right hand side can now also be calculated using.
![]() |
(8) |
The result of this calculation is that we now know the built in potential and minority carrier concentrations on both sides of the device.