Carrier concentration

[becon]

I have a homework on Solid state device
the question is :"If a Si sample is doped with 10^14 boron atoms per cm3 then determine the
carrier concentration in the Si sample at 300K."[/b]

I thought that the concentration is calculate by
n = 2[(2pi*u_n*kT/h^2)]^(3/2)
is this right formula ? How about the Nd = 10^14 ?

thank you.

 

[becon]

I thought it wrong.
I have tried and solve it like : Boron is acceptor then Na = 10^14
by the charge neutrality relationship, n + Nd = p + Na
this is doped semiconductor, then n = Nd - Na and p = ni^2 / n
but what is the value of Nd ?