If the frequency of light is $f$ and if $f \ge f_t$, where $f_t$ is the threshold frequency, electrons are emitted if light is shined on a metal surface. By my understanding, the light comes in and is absorbed by the atom. The atom then has too much energy and emits an electron. I don't remember much about nuclear decay, but when an atom has too much energy it can emit an alpha particle or a gamma ray or whatever else (something about decaying down to a stable line).
Anyways, so if an atom has too much energy and ejects an electron, is that considered a nuclear decay? Also, does the photoelectric effect then ionize materials? Could I take a metal sheet, shine light on it, and get a metal sheet that is now positive? Could I do this at home?