Question

Fermi energy Ef changes with applied electric field?

Answer 1

Electric potential changes Fermi level of charged particles. But ststic electric field can not almost penetrate to metals. Because the concentration of free electrons in metals is very high. The curent density is proportional to elementary charge, mobility, concentration of carge carriers and GRADIENT of FERMI LEVEL. So, even the curent density in metals is not zero, the gradient of Fermi level is close to zero.    

Answer 2

Explanation:

Electric potential changes Fermi level of charged particles. But ststic electric field can not almost penetrate to metals. Because the concentration of free electrons in metals is very high. The curent density is proportional to elementary charge, mobility, concentration of carge carriers and GRADIENT of FERMI LEVEL. So, even the curent density in metals is not zero, the gradie