Hi everyone, Thanks in advance for any insights you might be able to lead me to. The photoelectric effect is a well known phenomenon where an incident photon of some energy can stimulate the emission of an electron when absorbed, so long as the energy of the photon can promote an electron beyond the fermi level to the vacuum level of the material. Photons can also be regarded as waves, having an energy that is spread out over a statistical area until it interacts with a particle. In the double-slit experiment, photons (as well as other massive particles) have been shown to diffract and show interference patterns on a detector screen when going through a double slit. The famous result of the disappearance of this interference pattern when trying to observe which slit the photon travels through is something I've always admired. Coming back to the photoelectric effect, have any experiments been done to show a similar phenomenon in trying to "observe" where electrons are emitted and thus where photons are being absorbed? The motivating thought behind this is that if the photon acts as a wave prior to interaction with anything, and suddenly behaves as a discrete particle once it interacts with an electron in the material, it should be possible to detect the location of this interaction. Would this alter the photoelectric effect, since it too is reliant on diffraction? I realize the processes are not exactly parallel, but I would like to think that a similar phenomenon could be seen and, possibly, put to use for real-world applications.