As the electrons continue to diffuse
from n ® p, a layer of positive charge (or positive space-charge region) on
n-side of the junction is developed Similarly, when a hole diffuses from p ® n due to the concentration
gradient, it leaves behind an ionised acceptor (negative charge) which is
immobile As the holes continue to diffuse, a layer of negative charge (or
negative space-charge region) on the p-side of the junction is developed This space-charge region on either side of the junction together is known
as depletion region as the electrons and holes  taking
part in the initial movement across the junction depleted
the region of its free charges (Fig