Berlin 2015 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 37: Scanning Probe Techniques

O 37.15: Poster

Dienstag, 17. März 2015, 18:15–21:00, Poster A

Role of the tip in photon emission from Au surfaces in Scanning Tunneling Microscopy — •Berk Zengin, Hakki Tunç Çiftçi, and Oğuzhan Gürlü — Istanbul Technical University, Istanbul, Turkey

Photon emission induced by tunnelling current has been studied by means of photon scanning tunnelling microscopy (pSTM) since the advent of STM. Several reports had been published on the proper conditions of photon emission from the tip-Au surface tunnel junction. It has been shown that the tip material and its geometry play a serious role on the emitted photons. Yet, the variations on the Au surface as well as the photon emission maps were mainly related to the surface conditions. Our results show that tip cleanliness is one of the key reasons in the observed topography as well as on the photon maps. Moreover, the tunnelling current induced electromigration is also one of the events that happen at relatively high tunnelling current values. By use of different tips and tip preparation procedures we have shown that on similar thermally evaporated gold films, different results can be obtained by pSTM. Our results show that the results attained with pSTM cannot be interpreted without proper tip calibration.