High-energy resolution photoemission microspectroscopy: (1 1 1) domains featured by the Shockley and the image-potential states at a polycrystalline Cu surface

A photoemission microspectroscopy of 30meV energy resolution and 0.3μm lateral resolution has been applied to observe crystalline domains formed on a polycrystalline copper plate. Surface images based on the Shockley state specific to the (111) surface clearly showed many crystalline islands composed of the (111) surface. Similarly, surface images based on the unoccupied image-potential state were measured by employing two-photon photoemission spectroscopy. The high-energy resolution spectroscopy provides insight on the nm-scale surface morphology. The Shockley state was observed even on a poorly crystallized area, while the image-potential state was observed only on an area where mean (111) terrace length is sufficiently long.