# Semiconductor Doping Question

The question says:

Calculate the minority carrier life-time in Si having a donor concentration, NA = 1014 cm-3 if the diffusion length for minority carriers is 150 m.

Shouldnt it say "ND=1014"? because its a donor concentration and not an acceptor concentration?

Thanks

• I'm more curious about the 150m diffusion length – Dr Coconut Feb 4 '16 at 8:07

But yes, $N_D$ = donor concentration, $N_A$ = acceptor concentration.