The valency of impurity element for making p-type semiconductors is

The valency of the impurity atom in p-type semiconductor is

The valency of impurity element for using it as a donor for semiconductor is

The impurity atoms needed to make a p-type semiconductor are

The impurity atoms needed to make a p-type semiconductor are

The impurity atoms needed to make a p-type semiconductor are

The valency of an impurity element added to germanium or silicon crystal to prepare a p-type semiconductor is