What is Fermi energy? given the number of electrons and (L)

1. Oct 7, 2015

u061926

hi every body

question is :
Consider that 5.5E22 free electrons are confined in a potential barrier of length 3.2A . find its Fermi energy ???

the main point is that i was confident about the answer of question .. but the doctor said it is wrong .. he said i should use the relation between the number of electrons (N) to the volume (V) to get the density of charge(n) .. Even we learned that this relation used only in 3 dimensions and the question was about potential barrier which is one dimension which means that N=2n and n is fermi level and N is the number of conduction electrons .. am really con fused

Last edited: Oct 7, 2015
2. Oct 7, 2015

Simon Bridge

Perhaps the doc expected you to interpret the problem for 3D.
As written, it is not well worded.. i.e. particles may be confined in potential wells, not barriers.