Electrons diffuse from n to p while holes diffuse from p to n . The diffusion leaves behind bound charge in the lattice. The bound charge sets up an electric field that counteracts the diffusion.
Electrons drift from p to n while holes drift from n to p .
Raising potential of the p w.r.t n causes current to flow from p to n . Lowers potential barrier and diffusion dominates drift . Minority carriers injected into neutral region and diffuse toward plates. Recombine with majority carrier causing a net flow of current. Raising potential of the n w.r.t p causes current to flow from n to p .