it has been said that holes carry positive charge.But when electron leaves from a space hole isformed which is empty .Can a charge reside in a area which is empty?
This is like saying that charge has both property of reacting in a electric fiel
The concept of describes the lack of an electron at a position where one could exist in an atom or crystal lattice. And in crystal lattice the electron are not situated at any particular location, but there are continuous energy bands in which they reside. An imbalace is created when an electron jumps from one band to another, so that the atom has now a net positive charge. There is no empty space when an electron jumps from one energy band to another in crystal lattice.