do non-metal show photo-electric effect?

There is a practical consideration and a theoretical one. If you bombard a material with photons of a high enough energy to free an "outer-shell" electron, then these electrons will be able to separate from the molecule. That is the fundamental qualification for the photoelectric effect: the absorption of a large enough single quanta of energy that the electron can escape from its, well, affiliation with its 'home' molecule.
But in a non-conductor, what would that mean? The stability of all of the surrounding electrons would mean that it had no place to go. Remember that the electromagnetic force is a VERY strong force. (10 ^ 39 times stronger than gravity), so while in conductors, electrons can and do move around freely, they actually leave a neutral electromagnetic field at every point in the material. Of course, electrons and protons are not in exactly the same place, but on quite a strict average, and on an atomic or molecular scale, they do maintain a net neutrality.
So where would this newly free and liberated electron go? (A disco? A gay bar?) It turns out that it goes to the only place it is 'welcome':: right back where it began. it would take an enormous amount of energy to activate electrons from a large enough proportion of the molecules to give the electrons any real mobility.
So: yes, you can have a photoelectric effect for non-metals, but it is not very useful.

Thanks and Regards

Apoorva Arora

IIT Roorkee

askIITians Faculty