Re: n_i changes

[Vivek Subramanian]

Just to clarify... you will need to include bandgap narrowing, as discussed
in the project handout... in other words, you need to use the ni equation
identified by Richard, and then impose a correction for bandgap narrowing as
discussed in the handout.

-VS.

"Richard Fei Guo" <rf...@imail.EECS.Berkeley.EDU> wrote in message
news:ggtiog$1g9s$1...@agate.berkeley.edu...
> No, don't worry about bandgap effects on ni. The very last hint says to
> use p56
> of Pierret to help you code the ni equation.
>
> In article <ggthdn$1fug$1...@agate.berkeley.edu>,
> cs18...@imail.EECS.Berkeley.EDU
> (Benjamin Ryan joyce) writes:
>>
>>
>> I want to find out what N_i_a is for the emitter so I can calculate the
>> built
>> in voltage. Doesn't N_i change with doping though? Do we just assume it
>> is
>> still the original N_i equation given, or do we need to use
>>
>>
>> n_i = sqrt(N_c*N_v_) * exp(E_g/2kT)(The equation is on page 53 of the
>> book, #
>> 2.21) where E_g will be different based on the equation given in the
>> project
>> write up(Change in E_G_Emitter = .045*(log(N_E) - 18). Also, I am
>> presuming
> the
>> equation is what the new band gap is, not the change in the bandgap.
>>
>> Or is there a different calculation for getting n_i of the emitter area?
>> The
>> 2.21 would have to use the effective masses of holes and electrons and we
>> are
>> only given values of those in the book for T=300k and not given how the
>> effective masses change with Temperature which is why I think I might
>> have
> the
>> wrong equation?
>>
>>
>> Thanks