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Modeling >> Semiconductor Devices >> carrier concentration for equilibrium and perturbe
https://designers-guide.org/forum/YaBB.pl?num=1064145207

Message started by jason_class on Sep 21^st, 2003, 4:53am

Title: carrier concentration for equilibrium and perturbe
Post by jason_class on Sep 21^st, 2003, 4:53am

Hello Geoffrey and All,

I am not very sure about intrinsic carrier concentration ni.
For any given temperature, the ni X ni = constant?
Let's say for Temperature T1,
the electron concentration carrier is n1
while hole concentration carrier is p1
then p1 X n1 = ni X ni

Then Temperature T2,
the electron concentration carrier is n2
while hole concentration carrier is p2
then p2 X n2 = ni X ni

then for any Temperature Tx, px X nx is always equal to ni X ni , is
it correct?

Case 2
When a p type Silicon(with dopant 10e17) is excite by light, the
electron concentration n(initial) will increase to some n(excite)
value.

Is it true that n(initial) X 10e17 = ni X ni
then n(excite) X 10e17 = ni X ni

So it is true that for any time decay for carrier concentration
the n(excite1,2,3,..) X 10e17 = ni X ni =n(initial) X 10e17 ?

Thank you for any help given.

rgds
jason

Title: Re: carrier concentration for equilibrium and pert
Post by Geoffrey_Coram on Sep 23^rd, 2003, 1:40pm

jason_class wrote on Sep 21^st, 2003, 4:53am:

For any given temperature, the ni X ni = constant?

Let's write n_i²(T). When you write p1 X n1 = ni X ni and then p2 X n2 = ni X ni, you've lost the temperature dependence.
p(T) X n(T) = n_i²(T) always.

Quote:

When a p type Silicon(with dopant 10e17) is excite by light, the
electron concentration n(initial) will increase to some n(excite)
value.

Is it true that n(initial) X 10e17 = ni X ni
then n(excite) X 10e17 = ni X ni

No, that's not right, because that would imply n(initial) = n(excite).

Start with p(T) X n(T) = n_i²(T)

Initially, n(T) = n(initial) and p(T) = 10e17.

After excitation, n(T) = n(excite), but p(T) = ?

-Geoffrey

Title: Re: carrier concentration for equilibrium and pert
Post by jason_class on Sep 26^th, 2003, 7:32pm

Thank you Geoffrey!