Did you mean the photoelectric effect? I think transistors really exploit our understanding of conduction and valence bands of electrons (https://en.wikipedia.org/wiki/Electronic_band_structure, how to move electrons to the conduction bands, and then bias them so a large current can flow (https://en.wikipedia.org/wiki/Field-effect_transistor#Effect...). IIRC part of the nobel for the transistor was because they (Shockley) had built a theoretical model based on QM

There's no (visible) photons involved in silicon computers, although very similar solid state and vacuum tube devices are used to exploit the photoelectric effect, mainly for scientific measurement purposes.