Register to reply 
Definitions of some terms 
Share this thread: 
#1
May412, 10:28 AM

P: 2

hey guys i wanna know the definition of these terms & what are they but please i don't want big words because i won't understand i wanna understand it simply:
1Fermi level 2Density of states 3Carrier concentration & the graphs (in the attachment) 4Mass action law 5Charge neutrality i attached some files because i don't understand what it is saying 


#2
May412, 12:01 PM

P: 17

Do you have any chemistry background? Because the easiest way to think of the Fermi level is as your highest occupied orbital. The major difference is that in a crystal structure, your discrete atomic or molecular orbitals blend together into bands of energy levels (so it isn't a Highest Occupied Molecular Orbital, it is instead called the Fermi level). Your density of states diagram is then analogous to a molecular orbital diagram. The big difference is that you once again don't have discrete energy levels, you now have a probability distribution for possible electronic states.



#3
May412, 12:30 PM

P: 672

Fermi level: At zero temperature everything below is occupied, everything above is empty. At finite temperature things get smeared out a but, according to FermiDirac statistics.
Density of states: How many electrons can you fit at this energy? There can be occupied and unoccupied DoS, so you have to be a bit careful sometimes. Charge neutrality: Just what is says. Number of positive charges (holes and donors) = number of negative charges (electrons and acceptors) Mass action law: Read the equation. Concentration of holes times concentration of electrons is a constant. Carrier density: Number of mobile electrons that can carry an electric current. Depends on the DoS and the probability to find an electron or hole there (FermiDirac statistics) 


Register to reply 
Related Discussions  
Specific technical definitions of quantum terms  Quantum Physics  0  
Definitions of greatest and least elements in terms of strict orderings  Calculus & Beyond Homework  3  
Definitions of few physics terms  General Physics  1  
Definitions in terms of truthfunctions  Set Theory, Logic, Probability, Statistics  17 